U.S. patent number 10,705,424 [Application Number 15/628,711] was granted by the patent office on 2020-07-07 for negative-working photoresist compositions for laser ablation and use thereof.
This patent grant is currently assigned to Merck Patent GmbH. The grantee listed for this patent is AZ ELECTRONIC MATERIALS (LUXEMBOURG) S. R. L.. Invention is credited to Chunwei Chen, Weihong Liu, Ping-Hung Lu.
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United States Patent |
10,705,424 |
Chen , et al. |
July 7, 2020 |
Negative-working photoresist compositions for laser ablation and
use thereof
Abstract
A composition crosslinkable by broad band UV radiation, which
after cross-linking is capable of cold ablation by a UV Excimer
Laser emitting between 222 nm and 308 nm, where the composition is
comprised of a negative tone resist developable in aqueous base
comprising and is also comprised of a conjugated aryl additive
absorbing ultraviolet radiation strongly in a range between from
about 220 nm to about 310 nm. The present invention also
encompasses a process comprising steps a), b) and c) a) coating the
composition of claim 1 on a substrate; b) cross-linking the entire
coating by irradiation with broadband UV exposure; c) forming a
pattern in the cross-linked coating by cold laser ablating with a
UV excimer laser emitting between 222 nm and 308 nm. Finally the
present invention also encompasses The present invention also
encompasses a process comprising steps a'), b') c') and d') a)
coating the composition of claim 1 on a substrate; b) cross-linking
part of the coating by irradiation with broadband UV exposure
through a mask; c) developing the coating with aqueous base
removing the unexposed areas of the film, thereby forming a first
pattern; d) forming a second pattern in the first pattern by laser
cold laser ablating of the first pattern with a UV excimer laser
emitting between 222 nm and 308 nm.
Inventors: |
Chen; Chunwei (Whitehouse
Station, NJ), Liu; Weihong (Bridgewater, NJ), Lu;
Ping-Hung (Bridgewater, NJ) |
Applicant: |
Name |
City |
State |
Country |
Type |
AZ ELECTRONIC MATERIALS (LUXEMBOURG) S. R. L. |
Luxembourg |
N/A |
LU |
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Assignee: |
Merck Patent GmbH (Darmstadt,
DE)
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Family
ID: |
57589048 |
Appl.
No.: |
15/628,711 |
Filed: |
June 21, 2017 |
Prior Publication Data
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Document
Identifier |
Publication Date |
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US 20170285475 A1 |
Oct 5, 2017 |
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Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
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14976498 |
Dec 21, 2015 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
G03F
7/095 (20130101); G03F 7/033 (20130101); G03F
7/0382 (20130101); G03F 7/16 (20130101); G03F
7/2022 (20130101); G03F 7/168 (20130101); G03F
7/2024 (20130101); G03F 7/0035 (20130101); G03F
7/031 (20130101); G03F 7/162 (20130101); G03F
7/2053 (20130101); G03F 7/027 (20130101); G03F
7/0048 (20130101); G03F 7/038 (20130101); G03F
7/2006 (20130101); G03F 7/322 (20130101); G03F
7/2004 (20130101) |
Current International
Class: |
G03F
7/20 (20060101); G03F 7/32 (20060101); G03F
7/004 (20060101); G03F 7/095 (20060101); G03F
7/00 (20060101); G03F 7/038 (20060101); G03F
7/031 (20060101); G03F 7/033 (20060101); G03F
7/027 (20060101); G03F 7/16 (20060101) |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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1193557 |
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Apr 2002 |
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EP |
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06-328698 |
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Nov 1994 |
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JP |
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1994-328698 |
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Nov 1994 |
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JP |
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2001-324811 |
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Nov 2001 |
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JP |
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2001-324811 |
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Nov 2001 |
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JP |
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2008-106213 |
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May 2008 |
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JP |
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2008-276167 |
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Nov 2008 |
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JP |
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|
Primary Examiner: Angebranndt; Martin J
Attorney, Agent or Firm: Houlihan; Francis M.
Parent Case Text
This application is a United States Divisional Application which
claims priority to U.S. non-provisional application Ser. No.
14/976,498 filed Dec. 21, 2015, the contents of which is being
hereby incorporated herein by reference.
Claims
We claim:
1. A process comprising steps A, B and C: A coating on a substrate
a composition for a negative tone, aqueous base developable,
broadband UV resist which is also sensitive in the areas exposed to
broadband irradiation to subsequent cold laser ablation by an UV
Excimer Laser emitting at 308 nm wherein said composition consists
of components of type a-1), b-1), c-1) a solvent, d-1) a surfactant
and e-1) an inhibitor; wherein: a-1) are components for imparting
negative tone, aqueous base developable, broadband UV resist
behavior comprised of (i) is at least one polymeric resin
comprising a structure of the following formula: ##STR00009##
wherein each of R.sub.1b-R.sub.5b is independently selected from
the group consisting of H, F and CH.sub.3, R.sub.6b is selected
from the group consisting of a substituted aryl, unsubstituted
aryl, substituted heteroaryl and unsubstituted heteroaryl group;
R.sub.7b is a substituted or unsubstituted benzyl group; R.sub.8b
is selected from the group consisting of a linear or branched
C.sub.2-C.sub.10 hydroxy alkyl group and a C.sub.2-C.sub.10 hydroxy
alkyl acrylate; R.sub.9b is an acid cleavable group, v=10-40 mole
%, w=0-35 mole %, x=0-60 mole %, y=10-60 mole % and z=0-45 mole %,
(ii) is one or more free radical initiators activated by actinic
radiation, and (iii) is one or more crosslinkable acrylated
monomers capable of undergoing free radical crosslinking wherein
the acrylate functionality is greater than 1; b-1) is a cold laser
ablation excimer laser sensitizer component system consisting of
(II); ##STR00010## wherein R.sub.3 is selected from the group
consisting of hydrogen, an alkyl group, an alkylenefluoroalkyl
group, an alkylene aryl group, and an alkyleneoxyalkyl group and X
is selected from the group consisting of Cl, Br or I; and further
wherein said cold laser ablation excimer laser sensitizer component
system comprises from 2 to 10 wt % of the composition, and wherein
the composition is one which can be coated to a thickness from 30
to 60 microns; B cross-linking the entire coating by blanket
irradiation with broadband UV exposure; and C forming a pattern in
the cross-linked coating by cold laser ablating with a UV excimer
laser emitting at 308 nm.
2. The process of claim 1 wherein, b1), the conjugated aryl
additive is (II), is one wherein, R.sub.3 is an alkyl group, and X
is Cl.
3. The process of claim 1 where the broadband UV exposure is
between 350 and 450 nm.
4. The process of claim 1 wherein said solvent is selected from the
group consisting of propylene glycol mono-alkyl ethers, propylene
glycol alkyls, 2-heptanone, 3-methoxy-3-methyl butanol, butyl
acetate, diglyme, ethylene glycol monoethyl ether acetate, ethylene
glycol monomethyl ether, ethylene glycol monoethyl ether,
diethylene glycol monoethyl ether, ethylene glycol monoethyl ether
acetate, ethylene glycol monomethyl acetate, methyl ethyl ketone,
2-heptanone, monooxymonocarboxylic acid esters, methyl oxyacetate,
ethyl oxyacetate, butyl oxyacetate, methyl methoxyacetate, ethyl
methoxyacetate, butyl methoxyacetate, methyl ethoxyactetate, ethyl
ethoxyacetate, ethoxy ethyl propionate, methyl 3-oxypropionate,
ethyl 3-oxypropionate, methyl 3-methoxypropionate, ethyl
3-methoxypropionate, methyl 2-oxypropionate, ethyl 2-oxypropionate,
ethyl 2-hydroxypropionate, ethyl 3-hydroxypropionate, propyl
2-oxypropionate, methyl 2-ethoxypropionate, propyl 2-methoxy
propionate, propylene glycol monomethyl ether acetate and mixtures
thereof.
5. A process comprising steps A, B, C and D: A coating on a
substrate a composition for a negative tone, aqueous base
developable, broadband UV resist which is also sensitive in the
areas exposed to broadband irradiation to subsequent cold laser
ablation by an UV Excimer Laser emitting at 308 nm wherein, said
composition consists of components of type a-1), b-1), c-1) a
solvent, d-1) a surfactant and e-1) an inhibitor; wherein: a-1) are
components for imparting negative tone, aqueous base developable,
broadband UV resist behavior comprised of (i) is at least one
polymeric resin comprising a structure of the following formula:
##STR00011## wherein each of R.sub.1b-R.sub.5b is independently
selected from the group consisting of H, F and CH.sub.3, R.sub.6b
is selected from the group consisting of a substituted aryl,
unsubstituted aryl, substituted heteroaryl and unsubstituted
heteroaryl group; R.sub.7b is a substituted or unsubstituted benzyl
group; R.sub.8b is selected from the group consisting of a linear
or branched C.sub.2-C.sub.10 hydroxy alkyl group and a
C.sub.2-C.sub.10 hydroxy alkyl acrylate; R.sub.9b is an acid
cleavable group, v=10-40 mole %, w=0-35 mole %, x=0-60 mole %,
y=10-60 mole % and z=0-45 mole %, (ii) is one or more free radical
initiators activated by actinic radiation, and (iii) is one or more
crosslinkable acrylated monomers capable of undergoing free radical
crosslinking wherein the acrylate functionality is greater than 1;
b-1) is a cold laser ablation excimer laser sensitizer component
system consisting of (II); ##STR00012## wherein R.sub.3 is selected
from the group consisting of hydrogen, an alkyl group, an
alkylenefluoroalkyl group, an alkylene aryl group, and an
alkyleneoxyalkyl group and X is selected from the group consisting
of Cl, Br or I; and further wherein said cold laser ablation
excimer laser sensitizer component system comprises from 2 to 10 wt
% of the composition, and wherein the composition is one which can
be coated to a thickness from 30 to 60 microns, B cross-linking
part of the coating by irradiation with broadband UV exposure
through a mask; C developing the coating with aqueous base removing
the unexposed areas of the coating, thereby forming a first
pattern; D forming a second pattern in the first pattern by cold
laser ablating of the first pattern with a UV excimer laser
emitting at 308 nm.
6. The process of claim 5 wherein, b1), the conjugated aryl
additive (II), is one wherein R.sub.3 is an alkyl group, and X is
Cl.
7. The process of claim 5 wherein said solvent is selected from the
group consisting of propylene glycol mono-alkyl ethers, propylene
glycol alkyls, 2-heptanone, 3-methoxy-3-methyl butanol, butyl
acetate, diglyme, ethylene glycol monoethyl ether acetate, ethylene
glycol monomethyl ether, ethylene glycol monoethyl ether,
diethylene glycol monoethyl ether, ethylene glycol monoethyl ether
acetate, ethylene glycol monomethyl acetate, methyl ethyl ketone,
2-heptanone, monooxymonocarboxylic acid esters, methyl oxyacetate,
ethyl oxyacetate, butyl oxyacetate, methyl methoxyacetate, ethyl
methoxyacetate, butyl methoxyacetate, methyl ethoxyactetate, ethyl
ethoxyacetate, ethoxy ethyl propionate, methyl 3-oxypropionate,
ethyl 3-oxypropionate, methyl 3-methoxypropionate, ethyl
3-methoxypropionate, methyl 2-oxypropionate, ethyl 2-oxypropionate,
ethyl 2-hydroxypropionate, ethyl 3-hydroxypropionate, propyl
2-oxypropionate, methyl 2-ethoxypropionate, propyl 2-methoxy
propionate, propylene glycol monomethyl ether acetate and mixtures
thereof.
Description
Disclosed are novel compositions whose films coated on a substrate
are both phenolic negative tone crosslinking resist sensitive to
broadband UV radiation and in areas exposed to this broadband
radiation also are pattern-able by cold laser ablation with an
Excimer laser emitting at a wavelength between 222 nm and 308 nm
and also capable of being coated as thick films.
Also disclosed are novel methods of making relief images by imaging
films coated from this composition through cold laser ablation with
an excimer laser emitting at a wavelength between 222 nm and 308 nm
a film of these novel composition coated on a substrate that have
been previously been cross-linked by broadband exposure.
Also further disclosed is another novel method of making images
with the novel composition which is to cold laser ablate with an
excimer laser emitting at a wavelength between 222 nm and 308 nm a
topographical image previously imaged into a film of the novel
composition on a substrate by exposure with a Broadband UV exposure
through a mask and development with an aqueous base.
The relief images prepared from these novel compositions and
methods can be used in the formation of metal bumps and posts
useful for electronic innerlayer interconnections. They can also be
used as templates for electrochemical deposition of metal wiring
patterns. These photofabrication methods have found utility in such
application as chip scale packaging, microelectronic machine
systems, high density interconnections, liquid crystal devices,
organic transistors, light emitting diode, displays and the
like.
The manufacture of many electronic components can often only easily
be achieved with the use of thick film photosensitive photoresist
materials, compositions and methods. The process involves coating a
desired substrate with a photosensitive photoresist composition and
drying followed by exposing the photoresist to actinic radiation
through a photomask which contains the desired pattern of line
traces, bump holes and other structures. In the case of a negative
photoresist the exposed areas are hardened, while when exposing
through a mask the unexposed areas are removed by a suitable
developing solution, generally aqueous based. In many
photofabrication processes the thickness of the coated and dried
photoresist is required to be 30 microns while the line traces,
bump holes and other structures have dimension that can be at least
15 microns. Once the line traces, bumps and other structures are
fabricated the photoresist is removed in a stripping process again
typically using aqueously based solutions.
Cold laser ablation is achieved when the laser excitation results
in direct bond scission. Specifically, this is a photochemical
process in which the temperature of the system is unchanged. This
is typically done with a UV Excimer Laser emitting between 222 nm
and 308 nm.
The Inventive formulations of this application are comprised of a
negative tone resist which when coated on a substrate are sensitive
to broadband UV radiation whose imaging at this wavelength operates
through a crosslinking reaction induced by broadband radiation, but
which are also sensitivity to cold laser ablation with a UV Excimer
laser emitting between 222 nm and 308 nm.
These novel composition contain the following:
1) components which allow the composition to be coated as a thick
film on a substrate and impart to these coatings on a substrate the
property of being a negative tone, crosslinking, base developable
resist coating sensitive to broadband radiation and
2) at least one additional sensitizer component which after
broadband exposed film coated and exposed to broadband radiation
sensitivity to cold laser ablation.
The components for imparting negative tone broadband sensitivity a
base soluble resin comprised of phenolic moieties, carboxylic acid
moieties or a combination of both types moieties such that the
resin dissolves in aqueous base, an organic solvent which can
dissolve all components of the novel composition and make the
composition suitable for coating thick film on a substrate; at
least one crosslinker; at least one photoinitiator sensitive to
broadband irradiation.
The additive which sensitizes the coating composition to cold laser
ablation with an Excimer laser between 222 nm and 308 nm is
comprised of a conjugated aryl compound absorbing ultraviolet
radiation strongly from about 222 nm to about to about 310 nm.
In these novel composition the cross-linker is induced by broadband
irradiation to undergo a crosslinking reaction in the coated film
of the phenolic composition. This crosslinking induced by broadband
irradiation occurs through a mechanism where the phenolic resin and
the crosslinker are induced to undergo crosslinking by radical,
cation, acid or a combination of these moieties generated a
photoinitiator system sensitive to broadband UV irradiation.
The broadband photoinitiator system in this composition is
comprised of a photoacid generator additive, photoradical generator
additive or a combination of both type of photoinitiators. These
photoinitators may be inherently sensitive to broadband irradiation
or alternatively are sensitized to broadband irradiation by an
appropriate broadband sensitizer additive.
Areas of the composition coated on a substrate, not exposed to
broadband radiation maintain solubility in aqueous base while areas
exposed are crosslinked generating a negative tone image upon
aqueous base development.
Because this novel composition is also comprised of laser ablation
additives the coated films of this material, after broadband UV
exposed films are very susceptible cold laser ablation with an
Excimer laser emitting UV radiation between 222 nm and 308 nm
producing.
This invention also pertains for the novel use of such novel
coating formulations in two imaging approaches.
In the first approach, a cross-linked film is produced by blanket
flood exposure with broadband radiation of a film of the novel
composition cast on a substrate; images are then produced by
ablation with the Excimer laser in select areas of the cross-linked
film.
In the second imaging approach, an image produced by conventional
exposure of the of a film of the novel composition cast on a
substrate to broadband radiation through a mask followed by aqueous
base development and removal of the non-exposed area to produce a
first topographical image; however, this first topographical images
may subsequently be modified by cold Excimer laser ablation
ablating away selected topographical areas of first image.
In both kinds of processes, features such as deep contact holes,
vias and other topographical features are formed by cold laser
ablation that are be produced having stepper profiles, smoother
sidewalls with fewer Excimer laser pulse than conventional laser
ablation formulations.
Excimer Cold Laser ablation of conventional non-imageable,
non-crosslinking polymeric resins has several drawbacks as
follows:
Simple Polymer are susceptible to thermal flow unless a cure step
is added and the formulation is made to be thermally curable. Also,
the polymer needs to also be designed with a chemical resistance to
the etching processes subsequently employed for pattern transfer to
the substrate in the manufacture of MEM's Sensors and other
microelectronic components. Moreover, such polymers may not be
soluble in environmentally friendly spin casting solvents.
Negative broadband resists suitable as component in our novel laser
ablation composition must have several properties which make them
suitable for use as a component in our novel cold laser ablation
formulations as follows.
1) They must be imageable with broadband exposure.
2) Developable in aqueous base.
3) Imaged upon broadband exposure through the action of at least
one crosslinking additive which crosslinkable through the action of
an acid, a radical or both 4) Contain a photoacid generator,
photoradical generator which is inherently sensitive to broadband
or is sensitive to broadband when combined with a broadband
sensitizer.
5) Formulated in an environmentally safe spin casting solvent
The other component in our novel composition are additives which
impart sensitivity to cold laser ablation with an Excimer laser
emitting UV radiation between 222 nm and 308 nm. These additives
must impart to the above described negative resist a high ablation
rate with these Excimer lasers. They must also be soluble in the
environmentally safe spin casting solvent.
The novel compositions and processes of this invention solve the
problem of forming precise features in thick films 5-100 .mu.m
through cold laser ablation where the features have high aspect
ratios and also have high wall angles, and low sidewall roughness
and at the same time have a high ablation rate with an Excimer
laser emitting at a wavelength between 222 nm and 308 nm. The
ability to make such features is useful in the manufacturing of
MEMS, sensors and other microelectronic components.
SUMMARY OF THE INVENTION
A composition for a negative tone, aqueous base developable,
broadband UV resist which is also sensitive to in the areas exposed
to broadband irradiation to subsequent cold laser ablation by an UV
Excimer Laser emitting between 222 nm and 308 nm where the
composition is comprised of components a) and b) wherein; a) are
components for imparting negative tone, aqueous base developable,
broadband UV resist behavior comprised of i) a resin containing
phenolic moieties, carboxylic acid moieties or a combination of
both types moieties such that the resin dissolves in aqueous base;
ii) at least one cross-linker; iii) at least one photo-initiator
sensitive to broadband irradiation; and b) a cold laser ablation
excimer laser sensitizer component system comprised of at least one
conjugated aryl additive absorbing ultraviolet radiation strongly
in a range between from about 220 nm to about 310 nm The present
invention also encompasses a process comprising steps a), b) and c)
a) coating the composition of claim 1 on a substrate; b)
cross-linking the entire coating by irradiation with broadband UV
exposure; c) forming a pattern in the cross-linked coating by cold
laser ablating with a UV excimer laser emitting between 222 nm and
308 nm. Finally the present invention also encompasses The present
invention also encompasses a process comprising steps a'), b') c')
and d') a') coating the composition of claim 1 on a substrate; b')
cross-linking part of the coating by irradiation with broadband UV
exposure through a mask; c') developing the coating with aqueous
base removing the unexposed areas of the film, thereby forming a
first pattern; d') forming a second pattern in the first pattern by
laser cold laser ablating of the first pattern with a UV excimer
laser emitting between 222 nm and 308 nm.
DETAILED DESCRIPTION OF DRAWINGS
FIG. 1 Comparative Study Top Down SEM Pictures: Comparative
Formulation Example 1: and Formulation Example 1.
DETAILED DESCRIPTION
Throughout the present specification, unless otherwise stated the
terms used are described below.
As used herein, the conjunction "and" is intended to be inclusive
and the conjunction "or" is not intended to be exclusive unless
otherwise indicated. For example, the phrase "or, alternatively" is
intended to be exclusive.
As used herein the terms "photocure" and "photopolymerize" are used
interchangeably and refer to free radical initiated curing or
polymerization.
As used herein the term "dried" refers to films with less than 5%
solvent remaining after the drying process.
As used herein the term "thick film" refer to films which are
between 5-100 microns thick.
As used herein the term "phenolic" refers to an aryl moiety on
which at least one hydroxyl group is present attached to an
aromatic ring.
In the above definitions and throughout the present specification,
unless otherwise stated the terms used are described below.
Alkyl means linear or branched alkyl having the desirable number of
carbon atoms and valence. The alkyl group is generally aliphatic
and may be cyclic or acyclic (i.e. noncyclic). Suitable acyclic
groups can be methyl, ethyl, n- or iso-propyl, n-,iso, or
tert-butyl, linear or branched pentyl, hexyl, heptyl, octyl, decyl,
dodecyl, tetradecyl and hexadecyl. Unless otherwise stated, alkyl
refers to 1-10 carbon atom moiety. The cyclic alkyl groups may be
mono cyclic or polycyclic. Suitable example of mono-cyclic alkyl
groups include substituted cyclopentyl, cyclohexyl, and cycloheptyl
groups. The substituents may be any of the acyclic alkyl groups
described herein.
Suitable bicyclic alkyl groups include substituted
bicycle[2.2.1]heptane, bicyclo[2.2.2]octane, bicyclo[3.2.1]octane,
bicyclo[3.2.2]nonane, and bicyclo[3.3.2]decane, and the like.
Examples of tricyclic alkyl groups include
tricyclo[5.4.0.0..sup.2,9]undecane,
tricyclo[4.2.1.2..sup.7,9]undecane,
tricyclo[5.3.2.0..sup.4,9]dodecane, and
tricyclo[5.2.1.0..sup.2,6]decane. As mentioned herein the cyclic
alkyl groups may have any of the acyclic alkyl groups as
substituents.
Alkylene groups are divalent alkyl groups derived from any of the
alkyl groups mentioned hereinabove. When referring to alkylene
groups, these include an alkylene chain substituted with
(C.sub.1-C.sub.6)alkyl groups in the main carbon chain of the
alkylene group. Alkylene groups can also include one or more alkyne
groups in the alkylene moiety, where alkyne refers to a triple
bond. Essentially an alkylene is a divalent hydrocarbon group as
the backbone. Accordingly, a divalent acyclic group may be
methylene, 1,1- or 1,2-ethylene, 1,1-, 1,2-, or 1,3 propylene,
2,5-dimethyl-2,5-hexene, 2,5-dimethyl-2,5-hex-3-yne, and so on.
Similarly, a divalent cyclic alkyl group may be 1,2- or
1,3-cyclopentylene, 1,2-, 1,3-, or 1,4-cyclohexylene, and the like.
A divalent tricyclo alkyl groups may be any of the tricyclic alkyl
groups mentioned herein above. A particularly useful tricyclic
alkyl group in this invention is
4,8-bis(methylene)-tricyclo[5.2.1.0..sup.2,6]decane.
Aryl groups contain 6 to 24 carbon atoms including phenyl, tolyl,
xylyl, naphthyl, anthracyl, biphenyls, bis-phenyls, tris-phenyls
and the like. These aryl groups may further be substituted with any
of the appropriate substituents e.g. alkyl, alkoxy, acyl or aryl
groups mentioned hereinabove. Similarly, appropriate polyvalent
aryl groups as desired may be used in this invention.
Representative examples of divalent aryl groups include phenylenes,
xylylenes, naphthylenes, biphenylenes, and the like.
Alkoxy means straight or branched chain alkoxy having 1 to 10
carbon atoms, and includes, for example, methoxy, ethoxy,
n-propoxy, isopropoxy, n-butoxy, isobutoxy, tert-butoxy, pentyloxy,
hexyloxy, heptyloxy, octyloxy, nonanyloxy, decanyloxy,
4-methylhexyloxy, 2-propylheptyloxy, and 2-ethyloctyloxy.
Aralkyl means aryl groups with attached substituents. The
substituents may be any such as alkyl, alkoxy, acyl, etc. Examples
of monovalent aralkyl having 7 to 24 carbon atoms include
phenylmethyl, phenylethyl, diphenylmethyl, 1,1- or
1,2-diphenylethyl, 1,1-, 1,2-, 2,2-, or 1,3-diphenylpropyl, and the
like. Appropriate combinations of substituted aralkyl groups as
described herein having desirable valence may be used as a
polyvalent aralkyl group.
The term (meth)acrylate refers to methacrylate or acrylate, and
similarly, (meth)acrylic refers to methacrylic or acrylic.
The term acid cleavable group refers to a protecting group masking
a alcohol, phenol, or carboxylic acid functionality which can be
cleaved through a acid initiated catalytic process such as
acidolysis where or hydrolysis where the chain length of the
catalytic process entails a some juncture a sufficiently stable
carbocation intermediate to sustain a long catalytic chain.
Examples of such moieties are the following:
tertiary, secondary benzylic, secondary allylic, (or other
activated secondary carbocations containing a substituent
stabilizing the carbocation) which contain at least one proton on a
carbon atom adjacent capable of being abstracted to regenerate the
acid;
carbocation to which two oxygen atoms are attached to the carbon
containing the positive charge, such as are formed in the
hydrolysis of acetals and ketals;
silyl cations on which are attached three carbon atoms as are
formed in the hydrolysis of moieties such as trialkylsilyl ethers
or esters triarylsilyl ethers or ester, and diarylalkylsilyl ethers
or esters and the like. The term acid cleavable bond refers to the
bond undergoing acid catalyzed cleavage in the above acid cleavable
groups and the like.
Such acid cleavable groups are generally used in chemically
amplified resist processes were the acid originates from a
photo-acid generator (PAG) and the catalytic process amplifies the
quantum yield for photo-generation of acid. These groups may also
be cleaved by acid originating thermally from a thermal acid
generator (TAG). Materials which undergo ineffective hydrolysis
such as materials that undergo hydroxylis through a primary
carbocations, or unactivated secondary carbocations are not
considered as acid cleavable group nor are materials that undergo
ineffective hydrolysis through a tertiary or secondary carbocation
because they do not have an abstractable hydrogen to reform the
acid in an acidolysis process as described above.
Furthermore, and as used herein, the term "substituted" is
contemplated to include all permissible substituents of organic
compounds. In a broad aspect, the permissible substituents include
acyclic and cyclic, branched and unbranched, carbocyclic and
heterocyclic, aromatic and non-aromatic substituents of organic
compounds. Illustrative substituents include, for example, those
described hereinabove. The permissible substituents can be one or
more and the same or different for appropriate organic compounds.
For purposes of this invention, the heteroatoms such as nitrogen
may have hydrogen substituents and/or any permissible substituents
of organic compounds described herein which satisfy the valencies
of the heteroatoms. This invention is not intended to be limited in
any manner by the permissible substituents of organic
compounds.
Compositions
One aspect of this invention is a composition for a negative tone,
aqueous base developable, broadband UV resist which is also
sensitive to in the areas exposed to broadband irradiation to
subsequent cold laser ablation by an UV Excimer Laser emitting
between 222 nm and 308 nm where the composition is comprised of
components a) and b); a) components for imparting negative tone,
aqueous base developable, broadband UV resist behavior i) a resin
containing phenolic moieties, carboxylic acid moieties or a
combination of both types moieties such that the resin dissolves in
aqueous base; ii) at least one cross-linker; iii) at least one
photo-initiator sensitive to broadband irradiation; and b) a cold
laser ablation excimer laser sensitizer component system comprised
of at least one conjugated aryl additive absorbing ultraviolet
radiation strongly in a range between from about 220 nm to about
310 nm
In another aspect of this novel composition the conjugated aryl
additive in b) absorbing strongly from about 222 nm to about to
about 310 nm is chosen from (I), (II), (III), (IV), (V), (VI) and
(VII);
##STR00001## where R.sub.1, R.sub.2, R.sub.3, R.sub.4, R.sub.5 and
R.sub.6 are independently chosen from hydrogen, an alkyl group, a
alkylenefluoroalkyl group, an alkylene aryl group, and a
alkyleneoxyalkyl group; R.sub.7 is chosen from an alkyl group, a
alkylenefluoroalkyl group, an alkylene aryl group, and an
alkyleneoxyalkyl group; R.sub.8 substituents are independently
chosen from hydrogen, an alkyl group, a alkylenefluoroalkyl group,
an alkylene aryl group, an alkyleneoxyalkyl group, a hydroxy group,
a hydroxyalkylene group, and an alkoxy group; X is a halogen
selected from Cl, Br or I; and further where n, na, nb, m, ma and
mb are independently chosen from an integer from 1 to 4; mc is
chosen from an integer from 1 to 9, and and is chosen from an
integer from 1 to 10.
In another aspect of this invention the a) components imparting
negative tone aqueous base developability upon broadband
irradiation may be selected from composition imparting broadband UV
sensitivity as described in the following patent documents U.S.
Pat. Nos. 8,906,5095, 7,601,482 and 6,576,394. Each of the
documents referred to above are incorporated herein by reference in
its entirety, for all purposes.
In this aspect of this invention the a) components imparting
negative tone aqueous base developability upon broadband
irradiation may be selected from the a) the components for
imparting negative tone aqueous base developable, broadband UV
resist behavior are selected from the component groups (VIII),
(VIV) or (X) where,
Group (VIII)
In a first Embodiment of Group (VIII) it is comprised of: a) a
phenolic film forming polymeric binder resin having ring bonded
hydroxy group; b) a photoacid generator that forms an acid upon
exposure to radiation, in an amount sufficient to initiate
crosslinking of the film-forming binder resin; c) a crosslinking
agent that forms a carbonium ion upon exposure to the acid of b)
generated by exposure to radiation, and which comprises an
etherified amino-plast polymer or oligomer; d) a second
crosslinking agent that forms a carbonium ion upon exposure to the
acid of b) generated by exposure to radiation, and which comprises
dihydroxyalkyl-(tetra)-phenol, wherein the amount of c) and d) is
an effective crosslinking amount; and e) a photoresist solvent
In another embodiment of Group (VIII) is is comprised of the
following: a) a phenolic film-forming polymeric binder resin having
ring bonded hydroxyl groups; b) a photoacid generator that forms an
acid upon exposure to radiation, in an amount sufficient to
initiate crosslinking of the film-forming binder resin; c) a
crosslinking agent that forms a carbonium ion upon exposure to the
acid from step b) generated by exposure to radiation, and which
comprises an etherified am inoplast polymer or oligomer; d) a
second crosslinking agent that forms a carbonium ion upon exposure
to the acid from step b) generated by exposure to radiation, and
which comprises either: 1) a hydroxy substituted- or 2) a hydroxy
C.sub.1-C.sub.4 alkyl substituted-C.sub.1-C.sub.12 alkyl phenol,
wherein the total amount of the crosslinking agents from steps c)
and d) is an effective crosslinking amount; and e) a photoresist
solvent. a) Group (VIII) Resin Binders
In another embodiment of Group (VIII), the phenolic film-forming
polymeric binder resins utilized in the above described embodiments
are preferably a hydroxyaromatic polymers that are soluble in an
alkaline medium such as an aqueous alkaline developer, but
insoluble in water. These binder resins are capable of undergoing
crosslinking in the presence of a crosslinking agent. The binder
resins are chosen so that the photoresist compositions of the
present invention are soluble in alkaline medium, such as an
aqueous alkaline developer, before being crosslinked. However,
these compositions then become insoluble in such alkaline medium
after crosslinking.
Preferred binder resins in a type VIII component may comprise a
novolak, preferably derived from a substituted phenol such as
ortho-cresol; meta-cresol; para-cresol; 2,4-xylenol; 2,5-xylenol;
3,4-xylenol, 3,5-xylenol, thymol and mixtures thereof, that has
been condensed with an aldehyde such as formaldehyde. The binder
resin may also comprise a poly(vinyl phenol) such as a
poly(para-hydroxystyrene); a poly(para-hydroxy-alpha-methylstyrene;
a copolymer of para-hydroxystyrene or
para-hydroxy-alpha-methylstyrene and styrene, acetoxystyrene or
acrylic acid and/or methacrylic acid; a hydroxyphenylalkyl carbinol
homopolymer; or a novolak/poly(vinyl phenol) copolymer.
b) Group (VIII) Photoacid Generator
The photoacid generator, upon exposure broadband radiation
generates the amount of acid necessary to catalyze the crosslinking
of the polymeric binder resin in the photoresist composition. This
provides the final differences in solubility between the exposed
and unexposed areas of the photoresist film on the substrate. The
preferred photo-acid generator is a radiation sensitive oxime
sulfonate sensitive to broadband radiation, such as disclosed in
U.S. Pat. Nos. 4,540,598 and 5,627,011. As the photoresist of type
VIII, as a component in the current inventive composition for cold
laser ablation, is exposed to broadband radiation, the oxime
sulfonate PAG generates acid, so that crosslinking takes place
during the post exposure baking process, in which the exposed areas
of the photoresist composition become insoluble in the customary
alkaline medium, such as an aqueous alkaline developer.
Photoacid generators may have different chemical compositions. For
example, without limitation, suitable photoacid generators may be
onium salts, dicarboximidyl sulfonate esters, oxime sulfonate
esters, diazo(sulfonyl methyl) compounds, disulfonyl methylene
hydrazine compounds, nitrobenzyl sulfonate esters, biimidazole
compounds, diazomethane derivatives, glyoxime derivatives,
.beta.-ketosulfone derivatives, disulfone derivatives,
nitrobenzylsulfonate derivatives, sulfonic acid ester derivatives,
imidoyl sulfonate derivatives, halogenated triazine compounds,
equivalents thereof or combinations thereof.
Onium salt photoacid generators may comprise, without limitation,
alkyl sulfonate anions, substituted and unsubstituted aryl
sulfonate anions, fluoroalkyl sulfonate anions, fluoarylalkyl
sulfonate anions, fluorinated arylalkyl sulfonate anions,
hexafluorophosphate anions, hexafluoroarsenate anions,
hexafluoroantimonate anions, tetrafluoroborate anions, equivalents
thereof or combinations thereof. Specifically, without limitation
suitable photoacid generators may include triphenylsulfonium
trifluoromethanesulfonate, triphenylsulfonium
nonafluoro-n-butanesulfonate, triphenylsulfonium
perfluoro-n-octanesulfonate, and triphenylsulfonium
2-(bicyclo[2.2.1]heptan-2-yl)-1,1,2,2-tetrafluoroethanesulfonate,
4-cyclohexylphenyldiphenylsulfonium trifluoromethanesulfonate,
4-cyclohexylphenyldiphenylsulfonium nonafluoro-n-butanesulfonate,
4-cyclohexylphenyldiphenylsulfonium perfluoro-n-octanesulfonate,
4-cyclohexylphenyldiphenylsulfonium
2-(bicyclo[2.2.1]heptan-2-yl)-1,1,2,2-tetrafluoroethanesulfonate,
4-methanesulfonylphenyldiphenylsulfonium trifluoromethanesulfonate,
4-methanesulfonylphenyldiphenylsulfonium
nonafluoro-n-butanesulfonate,
4-methanesulfonylphenyldiphenylsulfonium
perfluoro-n-octanesulfonate, and
4-methanesulfonylphenyldiphenylsulfonium
2-(bicyclo[2.2.1]heptan-2-yl)-1,1,2,2-tetrafluoroethanesulfonate,
diphenyliodonium trifluoromethanesulfonate, diphenyliodonium
nonafluoro-n-butanesulfonate, diphenyliodonium
perfluoro-n-octanesulfonate, diphenyliodonium
2-(bicyclo[2.2.1]heptan-2-yl)-1,1,2,2-tetrafluoroethanesulfonate,
bis(4-t-butylphenyl)iodonium trifluoromethanesulfonate,
bis(4-t-butylphenyl)iodonium nonafluoro-n-butanesulfonate,
bis(4-t-butylphenyl)iodonium perfluoro-n-octanesulfonate,
bis(4-t-butylphenyl)iodonium
2-(bicyclo[2.2.1]heptan-2-yl)-1,1,2,2-tetrafluoroethanesulfonate,
1-(4-n-butoxynaphthalen-1-yl)tetrahydrothiophenium
trifluoromethanesulfonate,
1-(4-n-butoxynaphthalen-1-yl)tetrahydrothiophenium
nonafluoro-n-butanesulfonate,
1-(4-n-butoxynaphthalen-1-yl)tetrahydrothiophenium
perfluoro-n-octanesulfonate,
1-(4-n-butoxynaphthalen-1-yl)tetrahydrothiophenium
2-(bicyclo[2.2.1]heptan-2-yl)-1,1,2,2-tetrafluoroethanesulfonate,
1-(6-n-butoxynaphthalen-2-yl)tetrahydrothiophenium
trifluoromethanesulfonate,
1-(6-n-butoxynaphthalen-2-yl)tetrahydrothiophenium
nonafluoro-n-butanesulfonate,
1-(6-n-butoxynaphthalen-2-yl)tetrahydrothiophenium
perfluoro-n-octanesulfonate,
1-(6-n-butoxynaphthalen-2-yl)tetrahydrothiophenium
2-(bicyclo[2.2.1]heptan-2-yl)-1,1,2,2-tetrafluoroethanesulfonate,
1-(3,5-dimethyl-4-hydroxyphenyl)tetrahydrothiophenium
trifluoromethanesulfonate,
1-(3,5-dimethyl-4-hydroxyphenyl)tetrahydrothiophenium
nonafluoro-n-butanesulfonate,
1-(3,5-dimethyl-4-hydroxyphenyl)tetrahydrothiophenium
perfluoro-n-octanesulfonate,
1-(3,5-dimethyl-4-hydroxyphenyl)tetrahydrothiophenium
2-(bicyclo[2.2.1]heptan-2-yl)-1,1,2,2-tetrafluoroethanesulfonate
N-(trifluoromethanesulfonyloxy)bicyclo[2.2.1]hept-5-ene-2,3-dicarboximide-
,
N-(nonafluoro-n-butanesulfonyloxy)bicyclo[2.2.1]hept-5-ene-2,3-dicarboxy-
imide,
N-(perfluoro-n-octanesulfonyloxy)bicyclo[2.2.1]hept-5-ene-2,3-dicar-
boxyimide,
N-[2-(bicyclo[2.2.1]heptan-2-yl)-1,1,2,2-tetrafluoroethanesulfo-
nyloxy]bicyclo[2.2.1]hept-5-ene-2,3-dicarboxyimide,
N-[2-(tetracyclo[4.4.0.12,5.17,10]dodecan-3-yl)-1,1-difluoroethanesulfony-
loxy]bicyclo[2.2.1]hept-5-ene-2,3-dicarboxyimide,
1,3-dioxoisoindolin-2-yl trifluoromethanesulfonate,
1,3-dioxoisoindolin-2-yl nonafluoro-n-butane sulfonate,
1,3-dioxoisoindolin-2-yl perfluoro-n-octane sulfonate,
3-dioxoisoindolin-2-yl
2-(bicyclo[2.2.1]heptan-2-yl)-1,1,2,2-tetrafluoroethanesulfonate,
3-dioxoisoindolin-2-yl
N-[2-(tetracyclo[4.4.0.12,5.17,10]dodecan-3-yl)-1,1-difluoroethanesulfona-
te, 1,3-dioxo-1H-benzo[de]isoquinolin-2(3H)-yl
trifluoromethanesulfonate,
1,3-dioxo-1H-benzo[de]isoquinolin-2(3H)-yl nonafluoro-n-butane
sulfonate, 1,3-dioxo-1H-benzo[de]isoquinolin-2(3H)-yl
perfluoro-n-octanesulfonate,
1,3-dioxo-1H-benzo[de]isoquinolin-2(3H)-yl
2-(bicyclo[2.2.1]heptan-2-yl)-1,1,2,2-tetrafluoroethanesulfonate,
or 1,3-dioxo-1H-benzo[de]isoquinolin-2(3H)-yl
N-[2-(tetracyclo[4.4.0.12,5.17,10]dodecan-3-yl)-1,1-difluoroethanesulfona-
te,
(E)-2-(4-methoxystyryl)-4,6-bis(trichloromethyl)-1,3,5-triazine,
2-(Methoxyphenyl)-4,6-bis-(trichloromethyl)-s-triazine,
2-[2-(Furan-2-yl)ethenyl]-4,6-bis(trichloromethyl)-s-triazine,
2-[2-(5-methylfuran-2-yl)ethenyl)-4,6-bis(trichloromethyl)-s-triazine,
2-[2-(3,4-Dimethoxyphenyl)ethenyl]-4,6-bis(trichloromethyl)-s-triazine,
equivalents thereof or combinations thereof. Suitable photoacid
generators may also include onium salts comprising anions and
cations in combinations not shown supra.
c) Group (VIII) Crosslinkers Aminoplast
The etherified aminoplast crosslinking agent comprises an organic
oligomer or polymer that provides a carbonium ion upon and serves
to crosslink the film-forming binder resin in the presence of an
acid generated by radiation, preferably imaging radiation. This
renders the binder resin insoluble in an alkaline medium, in the
exposed areas. Such crosslinking agents may be prepared from a
variety of aminoplasts in combination with a compound or low
molecular weight polymer containing a plurality of hydroxyl,
carboxyl, amide or imide groups. Preferred amino oligomers or
polymers are aminoplasts obtained by the reaction of an amine, such
as urea, melamine, or glycolurea with an aldehyde, such as
formaldehyde. Such suitable aminoplasts include urea-formaldehyde,
melamine-formaldehyde, benzoguanamine-formaldehyde, and
gylcoluril-formaldehyde resins, and combinations of any of these. A
particularly preferred am inoplast is hexa(methoxymethyl) melamine
oligomer.
d) Group (VIII) Crosslinkers Hydroxy-Substituted Alkyl Phenol
The hydroxy-substituted alkyl phenol crosslinking agent comprises
an organic polymer that provides a carbonium ion and also serves to
crosslink the film-forming binder resin in the presence of an acid
generated by radiation. This renders the binder resin insoluble in
an alkaline medium, in the exposed areas. Such crosslinking agents
include mono- and di-hydroxy-substituted phenols such as a
dialkylol cresol, e.g. a dialkylol- (e.g. dimethylol-) para-cresol.
Preferred dialkylol cresols comprise mono- or di-hydroxy
C.sub.1-C.sub.4 alkyl substituted (mono-, di-, tri- or
tetra-C.sub.1-C.sub.12 alkyl) phenol, such as a
dihydroxyalkyl-(tetra-alkyl)-phenol. Particularly preferred
cross-linking agents are the 2,6-dihydroxyalkyl-4-(tetra-alkyl)
phenols, such as 2,6-dihydroxymethyl-4-(1,1,3,3-tetramethylbutyl)
phenol.
e) Group (VIII) Solvents
Suitable solvents for type VIII components and the conjugated aryl
additive absorbing ultraviolet radiation strongly from about 222 nm
to about to about 310 nm may include propylene glycol mono-alkyl
ether, propylene glycol alkyl (e.g. methyl) ether acetate,
2-heptanone, 3-methoxy-3-methyl butanol, butyl acetate, anisole,
xylene, diglyme, ethylene glycol monoethyl ether acetate, ethylene
glycol monomethyl ether, ethylene glycol monoethyl ether,
diethylene glycol monoethyl ether, ethylene glycol monoethyl ether
acetate, ethylene glycol monomethyl acetate, methyl ethyl ketone,
2-heptanone or a monooxymonocarboxylic acid ester, such as methyl
oxyacetate, ethyl oxyacetate, butyl oxyacetate, methyl
methoxyacetate, ethyl methoxyacetate, butyl methoxyacetate, methyl
ethoxyactetate, ethyl ethoxyacetate, ethoxy ethyl propionate,
methyl 3-oxypropionate, ethyl 3-oxypropionate, methyl
3-methoxypropionate, ethyl 3-methoxypropionate, methyl
2-oxypropionate, ethyl 2-oxypropionate, ethyl 2-hydroxypropionate
(ethyl lactate), ethyl 3-hydroxypropionate, propyl 2-oxypropionate,
methyl 2-ethoxypropionate, or propyl 2-methoxy propionate, or
mixtures of one or more of these. The photoresist solvent(s) may be
present in the overall photoresist composition in an amount of up
to 95% by weight of the solids in the composition. Solvents, of
course, are substantially removed after coating of the photoresist
solution on a substrate and subsequent drying.
As a non limiting Example in the novel laser ablation compositions
comprised of component VIII concentration of the phenolic film
forming polymeric binder resin can range from about 30 weight % by
total solids of the solution to about 50 to 80 weight % by solids,
the concentration of the photoacid generator can range from about 1
weight % by solids to about 8 weight % by solids, the concentration
of the Crosslinkers Aminoplast can range from about 10 weight % by
solids to about 40 weight % by solids, the Crosslinkers
hydroxy-substituted alkyl phenol can range from about 1 weight % by
solids to about 6 weight % by solids, and the concentration of the
conjugated aryl additive absorbing ultraviolet radiation strongly
from about 222 nm to about to about 310 nm ranges from about 0.1 to
10 weight %. Solvents, of course, are substantially removed after
coating of the novel laser ablation solution on a substrate and
subsequent drying.
Group (VIV)
In one embodiment of the type (VIV) component needed for imparting
negative tone resist behavior in the novel compositions capable of
cold Excimer laser ablation of this invention, this component is
comprised of the following: a-1) at least one alkali-soluble
polymer where the polymer comprises a least one unit of structure
(VIVa)
##STR00002## where R' is selected independently from hydroxy
(C.sub.1-C.sub.4) alkyl, chlorine, bromine and m' is an integer
from 1 to 4; b-1) at least one cross-linker monomer of structure
VIVb;
##STR00003## where, W is a multivalent linking group, R.sub.1a to
R.sub.6a are independently selected from hydrogen, hydroxy,
(C1-C20)alkyl and chlorine, X.sub.1 and X.sub.2 are independently
oxygen and n' is an integer equal to or greater than 1; and c-1) at
least on photoinitiator, and further where the monomer of structure
4 comprises an acid-cleavable group and the alkali soluble polymer
further comprises at least one acid-cleavelable group d-1) a
photoresist solvent
In another embodiment of the group (VIV) component it is comprised
of the following: a-1) An alkali soluble polymer which comprises at
least one unit of structure 1, referred to in the present
application as the unit comprising a phenolic group derived from
the hydroxystyrene monomer,
##STR00004## where, R' is selected independently from hydrogen,
(C.sub.1-C.sub.4)alkyl, chlorine, bromine and m is an integer from
1 to 4. The alkali soluble polymer of the negative photoresist of
the present invention may be synthesized from at least one
substituted or unsubstituted hydroxystyrene monomer. The
hydroxystyrene monomer may be 3-hydroxystyrene or 4-hydroxystyrene.
The hydroxystyrene monomer may be also selected from
3-methyl-4-hydroxystyrene, 3,5-dimethyl-4-hydroxystyrene, or
3,5-dibromo-4-hydroxystyrene. The polymer may be a homopolymer
comprising the unit of structure VIVa, or a copolymer comprising
the unit of structure VIVa and a unit derived from at least one
other monomer unit containing an unsaturated bond. Polymers that
comprise two or more types of monomeric units may be employed in
the present invention, for example forming a terpolymer or a
tetrapolymer. The comonomeric unit may be of structure (VIVc),
##STR00005## where, R'' is independently selected from hydrogen,
(C.sub.1-C.sub.4)alkyl, and R.sub.3c is a substituted or
unsubstituted aromatic group, hydrogen, substituted or
unsubstituted alicyclic group, linear or branched aliphatic group
containing 1 to 20 carbon atoms. R.sub.8 can further comprise
hetero atoms, such as those chosen from oxygen, nitrogen and
halogen (such as fluorine, chlorine and bromine) atoms to form
groups such as alcohol, ether, ester, amine, amide, pendant halide
groups or urethane. R.sub.8 may be exemplified by groups such as
substituted and unsubstituted phenyl; esters; aralkyl; alkyl
ethers; linear and branched alkyls, such as methyl, ethyl, propyl,
isopropyl, butyl, t-butyl, pentyl, hexyl and the like; cycloalkyls,
such as cyclohexyl, cycloheptyl, and the like; bicycloalkyls, such
as bicyclohexyl; adamantyls or cyano, amide, acetate, propionate,
pyrrolidone, carbazole, and halide (fluoride, chloride and
bromide), The comonomeric unit in the polymer may be further
described by structure (VIVd),
##STR00006## where R'' is independently selected from hydrogen and
(C.sub.1-C.sub.4)alkyl. R.sub.9 is a substituted or unsubstituted
aromatic group, substituted or unsubstituted alicyclic group,
linear or branched aliphatic group containing 1 to 20 carbon atoms
and hydrogen. R.sub.9 can further comprise hetero atoms such as
those chosen from oxygen, nitrogen and halogen atoms to form groups
such as alcohol, ether, ester, amine, amide or urethane. R.sub.9
may be exemplified by groups such as substituted and unsubstituted
phenyl; esters; aralkyl; alkyl ethers; linear and branched alkyls,
such as methyl, ethyl, propyl, isopropyl, butyl, t-butyl, pentyl,
hexyl and the like; cycloalkyls, such as cyclohexyl, cycloheptyl,
and the like; bicycloalkyls, such as bicyclohexyl; adamantyls.
The alkali soluble polymer may comprise an acid cleavable (labile)
bond, which in the presence of an acid makes the polymer even more
readily soluble in an aqueous alkali developer or a stripper. The
acid may be generated thermally and/or photochemically. The acid
cleavable bond, preferably comprises an acid cleavable C(O) OC,
C--O--C or C--O--Si bond. Examples of acid cleavable groups usable
herein include acetal or ketal groups formed from alkyl or
cycloalkyl vinyl ethers, silyl ethers formed from suitable
trimethylsilyl or t-butyl(dimethyl)silyl precursors, and
carboxylates formed from t-butyl acetate, amyl acetate,
1-alkylcycloalkyl acetate, or 1-alkyladamantyl acetate precursors.
Also useful are groups such as (tert-butoxycarbonyl)methyl and its
(C.sub.1-C.sub.6) alkyl analogs. The acid labile groups may be
pendant from the polymer backbone or pendant from groups attached
to the polymer backbone. The acid cleavable group may be formed by
partially capping the hydroxystyrene monomeric unit with a compound
containing the acid cleavable group and/or be incorporated in the
comonomer.
The comonomer is one capable of being polymerized with the
hydroxystyrene monomer forming the unit of structure (VIVa) in the
polymer, and may be exemplified by comonomers such as styrene,
vinylnaphthalene, 3- or 4-acetoxystyrene, (meth)acrylic acid,
(meth) acrylonitrile, methyl (meth)acrylate, t-butyl
(meth)acrylate, 1-methyl-cyclopentyl (meth)acrylate,
1-methyl-cyclohexyl (meth)acrylate, 2-m
ethyl-adamantyl-2-(meth)acrylate,
2-ethyl-adamantyl-2-(meth)acrylate,
2-butyl-adamantyl-2-(meth)acrylate, substituted or unsubstituted
hydroxystyrene with an acid cleavable group, an ethylenic comonomer
with an acid cleavable group, and norbornene derivative with an
acid cleavable group.
The polymer may be prepared from the corresponding monomers by any
suitable conventional polymerization process which react an
ethylenically unsaturated group. Such processes include, but are
not limited to free radical polymerization or ionic polymerization.
Such processes are typically run in solvent or solvent mixture
using a catalyst or initiator. Initiators can be chosen based on
the temperature to be employed in the polymerization. Examples of
suitable free radical initiators are benzoyl peroxide,
2,2'-azobisisobutyronitrile and lauroyl peroxide. Optionally, a
chain transfer agent may be included, such as 1-dodecanethiol.
The monomeric unit of structure VIVa may range from about 10 mole %
to about 100 mole % in one embodiment, from about 30 mole % to
about 80 mole % in another embodiment, and from about 40 mole % to
about 70 mole % in another embodiment.
The alkali soluble polymer of the present invention has a weight
average molecular weight ranging from about 2,000 to about 100,000,
preferably from about 3,000 to about 50,000, and more preferably
from about 5,000 to about 30,000. The polymer is present in the
formulation at levels ranging from about 5 to about 75 weight %,
preferably from about 10 to about 70 weight % by total solids of
the photoresist.
b-1) Group (VIV) Photopolymerizable Cross-Linker Monomer
The negative photoresist composition of Type VIV useful as a
component in the present invention also comprises a
photopolymerizable monomer, which is capable of polymerizing in the
presence of a photoinitiator and contains at least two ethylenic
unsaturated bonds. The photopolymerizable monomer is a
(meth)acrylate and can be illustrated by structure VIVb,
##STR00007## where, W is a multivalent linking group, R.sub.1a to
R.sub.6a are independently selected from hydrogen, hydroxy,
(C.sub.1-C.sub.20) alkyl and chlorine, X.sub.1 and X.sub.2 are
independently oxygen or N--R.sub.7a, where R.sub.7a is hydrogen or
(C.sub.1-C.sub.20) alkyl, and n is an integer equal to or greater
than 1. In one embodiment R.sub.7a is hydrogen or (C.sub.1-C.sub.4)
alkyl. In one embodiment X.sub.1 and X.sub.2 are oxygen. W is a
multivalent linking group, where W can be a small molecular moiety
or a polymer. Examples of multivalent W are a divalent, trivalent,
tetravalent, pentavalent, hexavalent and heptavalent moiety, and n
can range from 1 to about 7. The monomer may also be a polymer with
pendant vinyl groups, such as the acrylate groups in structure
VIVb, where W is a polymer. W can further be a linear or branched
alkylene group containing 1-20 carbon atoms; the alkylene group may
additionally contain one or more pendant hydroxy groups, alkyne
bonds, ester groups, ether groups, amide groups or other acceptable
organic groups. W may be (C.sub.2-C.sub.3) alkoxylated
(C.sub.1-C.sub.20) alkylene. In one embodiment W is a hydrocarbon
moiety containing only carbon and hydrogen atoms.
The above-mentioned polymerizable monomer is a polymerizable
compound having at least two ethylenic unsaturated double bonds in
a molecule, such as alkyl acrylates, hydroxyalkyl acrylates, alkyl
methacrylates or hydroxyalkyl methacrylates. Examples of the
polymerizable compound are not particularly limited and can be
appropriately selected depending on the purposes, and include
acrylic acid derivatives such as acrylic acid esters and
methacrylic acid derivatives such as methacrylic acid esters. The
polymerizable monomer may have a low molecular weight (monomer
property) or a high molecular weight (oligomer or polymer
property).
Examples of the polymerizable monomer containing two or more double
bonds include unsaturated esters, as shown in Structure VIVb. The
polymerizable monomer may be derived from the reaction of
unsaturated carboxylic acids or unsaturated acid chlorides with
compounds containing epoxy groups, more than 2 hydroxy groups
(polyols), two or more amino groups (polyamines), mixture of
hydroxyl and amino (amino alcohol) groups or mixtures of these
groups. Examples of the unsaturated carboxylic acids include
unsaturated fatty acids such as acrylic acid, methacrylic acid,
crotonic acid, itaconic acid, cinnamic acid, linoleic acid and
oleic acid. Among these, acrylic acid and methacrylic acid are
preferable. The equivalent acid chlorides to the above mentioned
unsaturated carboxylic acids may also be used. Suitable polyols are
aromatic and particularly aliphatic and alicyclic polyols. Examples
of the aliphatic and alicyclic polyols include alkylene diols
preferably having 2 to 12 carbon atoms such as ethylene glycol,
1,2- or 1,3-propenediol, 1,2-, 1,3- or 1,4-butanediol, pentanediol,
hexanediol, 2,5-hexanediol, octanediol, dodecanediol, diethylene
glycol, and triethylene glycol; polyethylene glycol having 200 to
1,500 molecular weight, 1,3-cyclopentanediol, 1,2-, 1,3-, or
1,4-cyclohexanediol, 1,4-dihydroxymethylcyclohexane, glycerol,
tris(.beta.-hydroxyethyl)amine, trimethylolethane,
trimethylolpropane, pentaerythritol, dipentaerythritol and
sorbitol. Aromatic polyols can be bisphenol A or its analogs.
Examples of amines are alkylene amines, and include 1,2-ethylene
diamine, 1,2- or 1,3-propylene diamine, diaminocyclohexane,
1,3-cyclohexanebismethylamine, 2,2-ethylenedioxybisethylamine and
the like. Examples of amino alcohols include 3-amino-1-propanol and
the like. Examples of epoxy compounds include 1,2,7,8-diepoxyethane
and the like.
Examples of the multi-unsaturated compound of a relatively high
molecular weight (oligomer/polymer property) include unsaturated
polyester resins generally produced from maleic acid, phthalic
acid, and one or more diols and having a molecular weight of about
500 to 3,000.
Polyols can be partially or completely esterified with one kind of
carboxylic acid or different types of unsaturated carboxylic acids
and in the partially esterified compounds, free hydroxyl may be
modified and, for example, esterified with other carboxylic
acids.
Examples of the polymerizable monomer are without limitation as
follows: 4,4'-bis(2-acryloyloxyethoxy)diphenyl propane, vinyl
acrylate, trimethylolpropane triacrylate, trimethylolethane
triacrylate, trimethylolpropane trimethacrylate, trimethylolethane
trimethacrylate, tetram ethylene glycol dimethacrylate, triethylene
glycol dimethacrylate, tetraethylene glycol diacrylate,
pentaerythritol diacrylate, pentaerythritol triacrylate,
pentaerythritol tetraacrylate, dipentaerythritol diacrylate,
dipentaerythritol triacrylate, dipentaerythritol tetraacrylate,
dipentaerythritol pentaacrylate, dipentaerythritol hexaacrylate,
tripentaerythritol octaacrylate, pentaerythritol dimethacrylate,
pentaerythritol trimethacrylate, dipentaerythritol dimethacrylate,
dipentaerythritol tetramethacrylate, tripentaerythritol
octamethacrylate, pentaerythritol diitaconate, dipentaerythritol
trisitaconate, dipentaerythritol pentaitaconate, dipentaerythritol
hexaitaconate, ethylene glycol diacrylate, 1,3-butanediol
diacrylate, 1,3-butanediol dimethacrylate, 1,4-butanediol
diitaconate, sorbitol triacrylate, sorbitol tetraacrylate,
pentaerythritol-modified triacrylate, sorbitol tetramethacrylate,
sorbitol pentaacrylate, sorbitol hexaacrylate, oligoester acrylate,
and methacrylate, glycerol diacrylate, and triacrylate,
1,4-cyclohexane diacrylate, bisacrylate and bismethacrylate of
polyethylene glycol with a molecular weight of 200 to 1,500 and
their mixtures.
Further examples for polymerizable monomers include 1,2-ethanediol
diacrylate, 1,2-propanediol diacrylate, 1,4-butanediol diacrylate,
hexan-1,6-diol diacrylate, dipropylene glycol diacrylate, neopentyl
glycol diacrylate, ethoxylated neopentyl glycol diacrylate,
propoxylated neopentyl glycol diacrylate, tripropylene glycol
diacrylate, bisphenol A diglycidylether diacrylate, ethoxylated
bisphenol A diglycidylether diacrylate, polyethylene glycol
diacrylate, trimethylolpropane triacrylate, ethoxylated
trimethylolpropane triacrylate, propoxylated trimethylolpropane
triacrylate, propoxylated glycerine triacrylate, tris(2-acryloyloxy
ethyl) isocyanurate, pentaerythritol triacrylate, ethoxylated
pentaerythritol triacrylate, pentaerythritol tetraacrylate,
ethoxylated pentaerythritol tetraacrylate, di(trimethylolpropane)
tetraacrylate, di(pentaerythritol) pentaacrylate,
di(pentaerythritol) hexaacrylate and oligomers and polymers
containing acrylate groups obtained by conversion of poly epoxides
with acrylic acid (epoxy acrylate) or by conversion of polyester
polyol with acrylic acid or monomeric alkyl acrylates (polyester
acrylates) or by conversion of isocyanate prepolymers with
2-hydroxyethyl acrylate ((polyurea acrylate) and acrylated soy bean
oil and acrylated silicone oil.
The photopolymerizable monomer may also comprise acid cleavable
groups which in the presence of an acid will cleave to form
compounds which increase the aqueous alkaline solubility of the
coating of the present invention. Such acid cleavable groups may be
C(O)--OC, C--O--C or C--O--Si groups within the monomer. Generally
known acid cleavable groups may be used. In one embodiment the acid
cleavable group comprises a tertiary carbon atom adjacent to an
oxygen atom or nitrogen atom (X.sub.1 and/or X.sub.2) of the
monomer of structure 4, and the tertiary carbon atom has
(C.sub.1-C.sub.5) alkyl groups attached to this carbon atom, that
is the monomer comprises a tertiary alkyl ester. Thus, W is a
(C.sub.1-C.sub.20) alkylene chain with tertiary carbon atoms at the
end of the chain linking to the acrylate end groups, where
2,5-dimethyl-2-5-hexene is an example of the linking group, W. Thus
W can be
C(R.sub.10R.sub.11)--(C.sub.1-C.sub.20)alkylene-C(R.sub.12R.sub.13),
where R.sub.10, R.sub.11, R.sub.12 and R.sub.13 are independently
selected from (C.sub.1-C.sub.5) alkyl groups. W may additionally
contain acid cleavable groups such C(O)--OC, C--O--C or C--O--Si
groups within the moiety. The acid may be generated thermally
and/or photochemically using thermal acid generators and/or
photoacid generators.
c-1) Group (VIV) Photoinitiator
In the photopolymerizable composition of component (VIV), the
composition contains at least one broadband photoinitiator or
broadband photoradical generating agent capable of generating a
radical upon exposure to a light source. Any photoiniator capable
of generating a radical upon exposure to radiation may be used. One
or more photoinitiators may be selected from those capable of
starting polymerization of the polymerizable compound contained in
the composition of the present invention and to be used as the
above-mentioned photoinitiator.
Examples of the above-mentioned broadband photoinitiator include
without limitation benzophenone, cam phorquinone,
4,4-bis(dimethylamino)benzophenone,
4-methoxy-4'-dimethylaminobenzophenone, 4,4'-dimethoxybenzophenone,
4-dimethylaminobenzophenone, 4-dimethylaminoacetophenone,
benzylanthraquinone, 2-tert-butylanthraquinone,
2-methylanthraquinone, xanthone, thioxanthone,
2-chlorothioxanthone, 2,4-diethylthioxanthone, fluorene, acridone,
bisacylphosphine oxides such as
bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide and the like,
.alpha.-hydroxy or .alpha.-aminoacetophenones,
.alpha.-hydroxycycloalkylphenylketones, and aromatic ketones such
as dialkoxyacetophenone; benzoin and benzoin ethers such as
benzoinmethyl ether, benzoinethyl ether, benzoinpropyl ether,
benzoinphenyl ether, and the like; 2,4,6-triarylimidazole dimers
such as 2-(o-chlorophenyl)-4,5-diphenylimidazole dimer,
2-(o-chlorophenyl)-4,5-di(m-methoxyphenyl)imidazole dimer,
2-(o-fluorophenyl)-4,5-diphenylimidazole dimer,
2-(o-methoxyphenyl)-4,5-diphenylimidazole dimer,
2-(p-methoxyphenyl)-4,5-diphenylimidazole dimer; and lophine dimer
compounds described in U.S. Pat. Nos. 3,784,557, 4,252,887,
4,311,783, 4,459,349, 4,410,621, 4,622,286 and the like:
polyhalogen compounds such as tetrabromocarbon,
phenyltribromomethylsulfone, phenyltrichloromethyl ketone and the
like; and compounds described in U.S. Pat. No. 3,615,455;
5-triazine derivatives (trihalomethyl compounds) having
trihalogen-substituted methyl, such as
2,4,6-tris(trichloromethyl)-S-triazine,
2-methoxy-4,6-bis(trichloromethyl)-S-triazine, 2-am
ino-4,6-bis(trichloromethyl)-S-triazine,
2-(P-methoxystyryl-4,6-bis(trichloromethyl)-S-triazine and the
like; organic peroxides, such as methyl ethyl ketone peroxide,
cyclohexanone peroxide, 3,3,5-trimethylcyclohexanone peroxide,
benzoyl peroxide, di-tert-butyl peroxyisophthalate,
2,5-dimethyl-2,5-di(benzoylperoxy)hexane, tert-butyl
peroxybenzoate, a,a'-bis(tert-butylperoxyisopropyl)benzene, dicumyl
peroxide, 3,3',4,4'-tetra-(tert-butylperoxycarbonyl)benzophenone
and the like; azinium compounds; organic boron compounds;
phenylglyoxalic acid esters such as phenylglyoxalic methyl ester;
titanocenes such as
bis(.eta..sup.5-2,4-cyclopentadien-1-yl)-bis(2,6-difluoro-3-(1H-pyrrol-1--
yl)-phenyl)titanium and the like; onium salt compounds such as
diaryliodonium salts and triarylsulfonium salts obtained by using
diphenyliodonium, 4,4'-dichlorodiphenyliodonium,
4,4'-dimethoxydiphenyliodonium, 4,4'-di-t-butylidiphenyliodonium,
4-methyl-4'-isopropyl-diphenyliodonium, or
3,3'-dinitrodiphenyliodonium in combination with chloride, bromide,
tetrafluoroborate, hexafluorophosphate, hexafluoroarsenate,
hexafluoroantimonate, tetrakis(pentafluorophenyl) borate, or
trifluoromethanesulfonic acid;
Preferred broadband photoinitiators for resist type (VIV) are those
available under the trade designations IRGACURE and DAROCUR from
Ciba Speciality Chemical Corp., Tarrytown, N.Y. and include
1-hydroxy cyclohexyl phenyl ketone (IRGACURE 184),
2,2-dimethoxy-1,2-diphenylethan-1-one (IRGACURE 651),
bis(2,4,6-trimethylbenzoyl)phenylphosphineoxide (IRGACURE 819),
1-[4-(2-hydroxyethoxy)phenyl]-2-hydroxy-2-methyl-1-propane-1-one
(IRGACURE 2959),
2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)butanone (IRGACURE
369), 2-methyl-1-[4-(methylthio)phenyl]-2-morpholinopropan-1-one
(IRGACURE 907), and 2-hydroxy-2-methyl-1-phenyl propan-1-one
(DAROCUR 1173). Particularly preferred photoinitiators are IRGACURE
819, 369 and 907.
Moreover, as the above-mentioned broadband photoinitiator, two or
more kinds of those exemplified compounds may be used in
combination. Examples thereof include the following: any
combinations of acrylphosphine oxides, alpha-hydroxy ketones and
alpha-amino ketones.
The combination of
2-methyl-1[4-(methylthio)phenyl]-2-morpholinopropan-1-one (Irgacure
907) and bis(2,4,6-trimethylbenzoyl)-phenylphosphineoxide (Irgacure
819) is used in one embodiment.
The photopolymerizable composition of the present invention may
further contain broadband sensitizers, such as isopropyl
thioxanthone and 3-keto cumarine, which absorb radiation at one
particular wavelength and transfer energy to the photosensitive
compound at a different wavelength.
d-1)) Group (VIV) Additional Components
d-1a)--Group (VIV) Accelerators
In addition the photopolymerizable composition of type (VIV) as
described above may in addition to component a-1), b-1) c-1) may
also contain so called accelerators, such as tributylamine,
N-methyl diethanolamine, N-butyl diethanolamine, triethanolamine,
piperidine, morpholine, piperazine, and acrylated amines, obtained
from 1,6-hexanediol diacrylate and ethanolamine tributylamine,
N-methyl diethanolamine, N-butyl diethanolamine, triethanolamine,
piperidine, morpholine, piperazine, and acrylated amines, obtained
from 1,6-hexanediol diacrylate and ethanolamine.
d-1b)--Group (VIV) Surfactants, Dyes, Plasticizers, Secondary
Polymers
The component of type VIV one of the possible component in the
present cold laser ablation invention may contain other components
such as additives, surfactants, dyes, plasticizers, and other
secondary polymers. Surfactants are typically compounds/polymers
containing fluorine or silicon compounds which can assist in
forming good uniform photoresist coatings. Certain types of dyes
may be used to provide absorption of unwanted light. Plasticizers
may be used, especially for thick films, to assist in flow
properties of the film, such as those containing sulfur or oxygen.
Examples of plasticizers are adipates, sebacates and phthalates.
Surfactants and/or plasticizers may be added at concentrations
ranging from about 0.1 to about 10 weight % by total weight of
solids in the photoresist composition. Secondary polymers may be
added to the composition of the present invention. These secondary
polymers provide properties that enhance the physical and
lithographic properties of the photoresist composition, such as
providing scum-free development. Polymers containing hydrophilic
groups are preferred. Examples of secondary polymers are
unsubstituted or substituted (meth)acrylic acid containing polymers
or copolymers, unsubstituted or substituted (meth)acrylate
containing polymers or copolymers, unsubstituted or substituted
vinyl ester containing polymers or copolymers, unsubstituted or
substituted vinyl aromatic containing polymers or copolymers,
(meth)acrylic acid-styrene copolymers and novolak polymers. Novolak
polymers can be prepared from polymerization of phenol, cresols,
di- and trimethy-substituted-phenols, polyhydroxybenzenes,
naphthols, polyhydroxynaphthols and other
alkyl-substituted-polyhydroxyphenols and formaldehyde, acetaldehyde
or benzaldehyde. Secondary polymers may be added at levels ranging
from about 0% to about 70%, preferably from about 10% to about 40%
of total solids of the photoresist.
In order to prevent inhibition of polymerization by oxygen, a waxy
compound, such as polyolefins, can be added to the composition. It
is believed that as a consequence of their appropriate solubility
in the mixtures, they float on top of the mixture at the start of
polymerization and form a thin protecting layer between atmospheric
oxygen and the polymerizing mixture. Additionally, auto-oxidizing
compounds like allyl ethers can be added that prevent inhibition of
polymerization by oxygen in some cases.
e-1) Group (VIV) Solvents
Suitable solvents for the novel composition for Excimer ablation of
this invention comprised of conjugated aryl additive absorbing
ultraviolet radiation strongly from about 222 nm to about to about
310 nm and the components of type may include, for example, a
glycol ether derivative such as ethyl cellosolve, methyl
cellosolve, propylene glycol monomethyl ether, diethylene glycol
monomethyl ether, diethylene glycol monoethyl ether, dipropylene
glycol dimethyl ether, propylene glycol n-propyl ether, or
diethylene glycol dimethyl ether; a glycol ether ester derivative
such as ethyl cellosolve acetate, methyl cellosolve acetate, or
propylene glycol monomethyl ether acetate; carboxylates such as
ethyl acetate, n-butyl acetate and amyl acetate; carboxylates of
di-basic acids such as diethyloxylate and diethylmalonate;
dicarboxylates of glycols such as ethylene glycol diacetate and
propylene glycol diacetate; and hydroxy carboxylates such as methyl
lactate, ethyl lactate, ethyl glycolate, and ethyl-3-hydroxy
propionate; a ketone ester such as methyl pyruvate or ethyl
pyruvate; an alkoxycarboxylic acid ester such as methyl
3-methoxypropionate, ethyl 3-ethoxypropionate, ethyl
2-hydroxy-2-methylpropionate, or methylethoxypropionate; a ketone
derivative such as methyl ethyl ketone, acetyl acetone,
cyclopentanone, cyclohexanone or 2-heptanone; a ketone ether
derivative such as diacetone alcohol methyl ether; a ketone alcohol
derivative such as acetol or diacetone alcohol; lactones such as
butyrolactone; an amide derivative such as dimethylacetamide or
dimethylformamide, anisole, and mixtures thereof. These solvent in
addition to dissolving the type VIV component must also dissolve
the conjugated aryl additive absorbing ultraviolet radiation
strongly from about 222 nm to about to about 310 nm
As a non-limiting Example in the novel laser ablation compositions
comprised of component VIV concentration of the polymer can range
from about 10 weight % by total solids of the composition for laser
ablation to about 50 (80) weight % by solids, the concentration of
the monomer can range from about 10 weight % by solids to about 50
or to about 80 weight % by solids, the concentration of the
photo-initiator can range from about 0.5 weight % by solids to
about 20 weight % by solids, and the concentration of the
conjugated aryl additive absorbing ultraviolet radiation strongly
from about 222 nm to about to about 310 nm ranges from about 0.1 to
10 weight %. Solvents, of course, are substantially removed after
coating of the novel laser ablation solution on a substrate and
subsequent drying.
Group (X)
In one embodiment of the type (X) component needed for imparting
broadband negative tone resist behavior in the novel compositions
capable of cold Excimer laser ablation of this invention, this
component is comprised of the following:
In another embodiment of the type (X) component needed for
imparting broadband negative tone resist behavior in the novel
compositions capable of cold Excimer laser ablation of this
invention, this component is comprised of components a-2 to d-2
wherein a-2 is at least one polymer comprising a structure of the
following formula (Xa):
##STR00008## wherein R.sub.1b-R.sub.5b is independently H, F or
CH.sub.3, R.sub.6 is selected from a group consisting of a
substituted aryl, unsubstituted aryl, substituted heteroaryl group
and unsubstituted heteroaryl group, R.sub.7b is a substituted or
unsubstituted benzyl group, R.sub.8b is a linear or branched
C.sub.2-C.sub.10 hydroxy alkyl group or a C.sub.2-C.sub.10 hydroxy
alkyl acrylate and R.sub.9 is an acid cleavable group, v=10-40 mole
%, w=0-35 mole %, x=0-60 mole %, y=10-60 mole % and z=0-45 mole %.
b-2) one or more free radical initiators activated by broadband
radiation, c-2) one or more crosslinkable acrylated monomers
capable of undergoing free radical crosslinking wherein the
acrylate functionality is greater than 1, and d-2) a solvent.
In another embodiment of the above embodiments the type X
composition is capable of being solubilized in aqueous alkaline
developer prior to crosslinking the acrylate monomers.
In another embodiment of the above embodiments the type X
compositions of the above embodiments further comprising at least
one polymer comprising the reaction product of styrene and at least
one acid containing monomer or maleic anhydride, said anhydride
reaction product being further partially esterified with an
alcohol.
In another embodiment of the above embodiments the type X
compositions of the above embodiments further comprising one or
more crosslinkable acrylated siloxane or acrylated silsesquioxane
based monomers capable of undergoing free radical crosslinking
wherein the acrylate functionality is greater than 1.
a-2) Other Embodiments of Polymer Comprising a Structure of Formula
(Xa)
In one embodiment of the composition of type (X) the polymer
comprising a structure (Xa) is one in which R.sub.1b through
R.sub.5b are independently a methyl group, hydrogen or fluoride.
R.sub.1b through R.sub.5b may be the same or different depending on
the desired properties of the polymer. One of the components of the
polymer contains a carboxylic acid prepared from the appropriate
acrylic acid monomer, wherein R.sub.1b is methyl, a hydrogen atom,
or a fluoride atom. R.sub.6b is a substituted or unsubstituted aryl
group, such as, for example, phenyl, tolyl, xylyl, naphthyl,
anthracyl, biphenyl, triphenyl and the like substituted with
C.sub.1-C.sub.24 alkyl or alkenyl groups or other functional group
as well as 5, 6 and 7 ring heterocyclic aromatic groups such as
azoles, thiazoles, oxazoles, pyridine, pyridazine, and the like.
R.sub.7b is a substituted or unsubstituted benzyl group which may
be substituted with, for example, C.sub.1-C.sub.24 alkyl or alkenyl
groups or other functional groups. R.sub.8b is a linear or
branched, C.sub.2-C.sub.10 hydroxy alkyl group or a
C.sub.2-C.sub.10 hydroxy alkyl acrylate such as for example,
wherein the hydroxy group is attached to the second carbon in the
chain such as, --CH.sub.2--CH.sub.2--OH,
--CH.sub.2--CH(OH)--CH.sub.3, or
--CH.sub.2--CH(OH)--CH.sub.2--CH.sub.3 as well as wherein the
hydroxy group is attached to the third carbon in the chain or other
carbon. The hydroxy alkyl acrylate may be and methacrylated
glycerol acrylate,
--CH.sub.2--CH(OH)--CH.sub.2OC(O)C(.dbd.CH.sub.2)CH.sub.3.
In another embodiment the polymer comprising a structure (Xa) may
further comprise other co-monomeric units, such as ones derived
from cyclopentadienyl acrylate and campholyl acrylate. These
additional co-monomeric units may be present at 0-30 mole %.
Non limiting example of the acid labile group R.sub.9b are for
example, a t-butyl group, a tetrahydropyran-2-yl group, a
tetrahydrofuran-2-yl group, a 4-methoxytetrahydropyran-4-yl group,
a 1-ethoxyethyl group, a 1-butoxyethyl group, a 1-propoxyethyl
group, a 3-oxocyclohexyl group, a 2-methyl-2-adamantyl group, a
2-ethyl-2-adamantyl group, a 8-methyl-8-tricyclo[5.2.1.0 2,6]decyl
group, a 1,2,7,7-tetramethyl-2-norbornyl group, a 2-acetoxymenthyl
group, a 2-hydroxymethyl group a 1-methyl-1-cyclohexylethyl group,
a 4-methyl-2-oxotetrahydro-2H-pyran-4-yl group, a
2,3-dimethylbutan-2-yl group, a 2,3,3-trimethylbutan-2-yl group, a
1-methyl cyclopentyl group, a 1-ethyl cyclopentyl group, a 1-methyl
cyclohexyl group, 1-ethyl cyclohexyl group, a
1,2,3,3-tetramethylbicyclo[2.2.1]heptan-2-yl group, a
2-ethyl-1,3,3-trimethylbicyclo[2.2.1]heptan-2-yl group, a
2,6,6-trimethylbicyclo[3.1.1]heptan-2-yl group, a
2,3-dimethylpentan-3-yl group, or a 3-ethyl-2-methylpentan-3-yl
group or other group that is cleaved when exposed to acid leaving
behind a carboxylic acid group.
In one embodiment of this invention v in structure (Xa) is between
about 10 and about 40 mole %, w is between about 0 and about 35
mole %, x is between about 0-60 mole %, y is between about 10-60
mole % and z is between about 0-45 mole %. The general formula (Xa)
above is not meant to show the exact positioning of the component
parts of the polymer so that the parts may exist together randomly,
as well, 2 or more of the same component part may exist
side-by-side in the polymer.
In accordance with the above embodiments, with reference to (Xa),
an exemplary molar percentage range for v may be 10-30 mole %. A
further exemplary molar percentage range for v may be 15-25 mole %.
An exemplary molar percentage range for w may be 0-25 mole %. A
further exemplary molar percentage range for w may be 0-20 mole %.
An exemplary molar percentage range for x may be 0-50 mole %. A
further exemplary molar percentage range for x, when present, may
be 30-55 mole %. An exemplary molar percentage range for y may be
20-45 mole %. A further exemplary molar percentage range for y may
be 25-40 mole %. An exemplary molar percentage range for z may be
0-35 mole %. A further exemplary molar percentage range for z, when
present, may be 25-40 mole %. Mole percentages are not independent
in that they must add to 100%.
a-2a) Other Polymer Components
The compositions may also include one or more polymers whose
carboxylic acid prepared from the appropriate acrylic acid monomer,
wherein R.sub.1b is methyl, a hydrogen atom, or a fluoride atom, is
replaced by a succinic acid half ester prepared by polymerizing
maleic anhydride with other selected monomers to create a polymer
and then reaction of the anhydride with an alcohol to create a
carboxylic acid and an ester.
The polymers of the composition of the present composition can be
prepared by any of the known methods for preparing
polyacrylates.
b-2) Free Radical Initiators Activated by Broadband Radiation
Component X may further contain one or more free radical initiators
or initiator systems activated by broadband radiation. A single
photoinitiator or a photoinitiator system containing multiple
components may be used. The photoinitiator can be of a specific
type, such as a halogenated-2,5cyclohexadienone, benzophenone,
alkylaryl ketone or diketone type, or mixtures thereof. Any of a
variety of free radical generating photoinitiators can be used in
the current invention. Benzophenone derivatives such as
benzophenone, bis-4,4'-dimethylam inobenzophenone (Michler's
ketone), bis-4,4'-diethylaminobenzophenone (ethyl Michler's
ketone), benzophenones singly or multiply substituted with other
alkylamino groups, chloro, methoxy, etc. are suitable. Also
substituted xanthones, thioxanthones, anthrones, and fluorenones
are useful initiators, as well as alkyl, chloro, and alkoxy
substituted thioxanthones. Substituted cyclohexadienones can be
also be used, such as with both an alkyl and a trichloromethyl
substituent in the 4 position. Useful alkylarylketone derivatives
include ketaldonyl alcohols such as benzoin, pivaloin, and acyloin
ethers such as benzoin alkyl ethers, benzoin aryl ethers,
alphahydrocarbon substituted aromatic acyloins, benzoin dialkyl
ketals, benzil, benzoin esters, O-acylated oximinoketones, and
alpha-amino ketones such as alpha-aminoactophenone derivatives.
Substituted or unsubstituted polynuclear quinones such as
9,10-anthroquinones, 1,4-naphthquinones, and phenanthrene quinones
are also possible initiators. Tertiary amines suitable as electron
and or hydrogen donors can also be used as part of the initiating
system such as substituted N,N-dialkylaminobenzene derivatives and
ethyl-4-(dimethylamino)benzoate. Useful diketones include biacetyl,
2,3-dibenzoyl-2-norbornene, benzoylbenzal chloride,
2,2-dibromo-2(phenylsulfonyl)propanedione, alpha-naphthyl,
2,3-bornanedione, phenylpuruvic acid and 2,4-pentanedione.
Representative quinones that can be used include 4-benzoquinone,
2-benzo-quinonediazide, anthraquinone, 2-methylanthraquinone,
2,6-dimethoxyanthra-quinone, 2,4,8-trichloroanthraquinone, amino
anthraquinone, 1,4-napthoquinone derivatives and
phenanthrenequinones. Also useful as photoinitiators are
2,4,5-triphenylimidazolyl dimers in combination with chain transfer
agents, or hydrogen donors.
c-2) Crosslinkable Acrylated Monomers Capable of Undergoing Free
Radical Crosslinking wherein the Acrylate Functionality is Greater
than 1
Component X may further contain one or more crosslinkable acrylated
monomers capable of undergoing free radical crosslinking, wherein
the acrylate functionality is greater than 1. Suitable monomers
include 1,4-butanediol diacrylate, 1,5-pentanedioldiacrylate,
diethylene glycol diacrylate, hexamethylene glycol diacrylate,
1,3-propanediol diacrylate, decamethylene glycol diacrylate,
decamethylene glycol dimethacrylate, 1,4-cyclohexanediol
diacrylate, 2,2-dimethylolpropane diacrylate, glycerol diacrylate,
glycerol triacrylate, trimethylolpropane triacrylate,
pentaerythritol triacrylate, polyoxyethylated trimethylolpropane
tri(meth)acrylate, polypropoxylated trimethylolpropane tri(meth)
acrylate and similar compounds, 2,2-di(p-hydroxyphenyl)propane
diacrylate, pentaerythritol tetraacrylate,
2,2di(p-hydroxyphenyl)propane dimethacrylate, triethylene glycol
diacrylate, polyoxyethyl-2,2-di(p-hydroxyphenyl)propane
dimethacrylate, bisphenol A diacrylate,
di-(3-methacryloxy-2-hydroxypropyl)ether of bisphenol A,
di-2-methacryloxyethyl ether of bisphenol A,
di-(3-acryloxy-2-hydroxypropyl)ether of bisphenol A,
di-2acryloxyethyl ether of bisphenol A, di-(3-methacryloxy-2-5
hydroxypropyl)ether of tetrachloro-bisphenol A,
di-2methacryloxyethyl ether of tetrachloro-bisphenol A,
di-(3methacryloxy-2-hydroxypropyl)ether of tetrabromobisphenol A,
di-2-methacryloxyethyl ether of tetrabromobisphenol A,
di-(3-methacryloxy-2-hydroxypropyl)ether of 1,4-butanediol,
triethylene glycol dimethacrylate, trimethylolpropane
trimethacrylate, ethylene glycol dimethacrylate, butylene glycol
dimethacrylate, 1,3-propanediol dimethacrylate, 1,2,4-butanetriol
trimethacrylate, 2,2,4trimethyl-1,3-pentanediol dimethacrylate,
1,2,4-butanetriol trimethacrylate, 2,2,4-trimethyl-1,3-pentanediol
1,5 dimethacrylate, pentaerythritol trimethacrylate,
1-phenylethylene-1,2-dimethacrylate, pentaerythritol
tetramethacrylate, 1,5-pentanediol dimethacrylate, 1,4-benzenediol
dimethacrylate, 1,3,5-triisopropenyl benzene and polycaprolactone
diacrylate.
d-2) A Solvent
Solvents useful in embodiments of the inventive laser ablation
composition containing component X are selected from the group
consisting of C.sub.1-C.sub.4 alcohols, C.sub.4-C.sub.8 ethers,
C.sub.3-C.sub.6 ketones, C.sub.3-C.sub.6 esters, and mixtures
thereof. Examples of C.sub.1-C.sub.4 alcohols include methanol,
ethanol, 1-propanol, and 2-propanol. Examples of C.sub.4-C.sub.8
ethers include diethyl ether, dipropyl ether, dibutyl ether and
tetrahydrofuran. Examples of C.sub.3-C.sub.6 ketones include
acetone, methyl ethyl ketone and cyclohexanone. Examples of
C.sub.3-C.sub.6 esters include methyl acetate, ethyl acetate and
n-butyl acetate.
Examples of suitable organic solvents for include ketones such as
acetone, methyl ethyl ketone, cyclohexanone, methyl isoamyl ketone,
methyl amyl ketone, and the like, polyhydric alcohols and
derivatives thereof such as monomethyl, monoethyl, monopropyl,
monobutyl and monophenyl ethers of ethyleneglycol, ethyleneglycol
monoacetate, diethyleneglycol, diethyleneglycol monoacetate,
propyleneglycol, propyleneglycol monoacetate, dipropyleneglycol or
dipropyleneglycol monoacetate and the like, cyclic ethers such as
dioxane, tetrahydrofuran and the like, esters such as methyl
lactate, ethyl lactate, methyl acetate, ethyl acetate, butyl
acetate and the like and solvents having aromatic groups such as
anisole, ethyl benzene, xylenes, chlorobenzene, toluene and the
like. Examples are propyleneglycol monomethyl ether acetate,
propyleneglycol monomethyl ether and ethyl lactate.
Solvents having one or more polar functional groups such as
hydroxyl, ether, amide, ester, ketone, and carbonate, for example,
two functional groups, which may be the same or different, such as
two hydroxyl groups or one hydroxyl group and one ether group,
including, for example, polyol, glycol ether, diacetone alcohol,
2-pyrrolidinone, N-methylpyrrolidinone, ethyl lactate, propylene
carbonate, 1,3-dimethyl-2-imidazolidindione, and alkyl esters, and
any combination thereof can be used.
For example, polyols such as polyethylene glycol, polypropylene
glycol, poly(ethylene-co-propylene glycol), polyvinyl alcohol,
trimethylol propane, ethylene glycol, glycerin, diethylene glycol,
triethylene glycol, tripropylene glycol, tetraethylene glycol,
pentaethylene glycol, 1,2-propylene glycol, 1,3-propanediol,
butylene glycol, triethylene glycol, 1,2,6-hexanetriol,
thiodiglycol, hexylene glycol, bis-2-hydroxyethyl ether,
1,4-butanediol, 1,2-butenediol, 1,4-butenediol, 1,3-butenediol,
1,5-pentanediol, 2,4-pentanediol, 2,4-heptanediol, 1,8-octanediol,
1,10-decanediol, 1,12-dodecanediol, 1,4-cyclohexanediol,
1,4-cyclohexanedimethanol, 1,2-bis(hydroxymethyl)cyclohexane,
1,2-bis(hydroxyethyl)-cyclohexane, 3-methyl-1,5-pentanediol,
2,2,4-trimethyl-1,3-pentanediol, neopentyl glycol, pentaerythritol,
sorbitol, mannitol, and any combination thereof, including
polyethylene glycol, trimethylol propane, ethylene glycol,
glycerin, diethylene glycol, tripropylene glycol, and any
combination thereof, can be used.
For example, glycol ethers such as ethylene glycol monomethyl
ether, ethylene glycol monoethyl ether, propylene glycol monomethyl
ether, tripropylene glycol monomethyl ether, ethylene glycol
monobutyl ether, diethylene glycol monomethyl ether, diethylene
glycol monoethyl ether, propylene glycol n-propyl ether, propylene
glycol t-butyl ether, propylene glycol n-butyl ether, dipropylene
glycol methyl ether, dipropylene glycol n-propyl ether, dipropylene
glycol t-butyl ether, dipropylene glycol n-butyl ether,
tripropylene glycol n-propyl ether, tripropylene glycol t-butyl
ether, tripropylene glycol n-butyl ether, ethyl cellosolve, methyl
cellosolve, polyethylene glycol monomethyl ether, polypropylene
glycol monomethyl ether, methoxytriglycol, ethoxytriglycol,
butoxytriglycol, 1-butoxyethoxy-2-propanol, and any combination
thereof, including ethylene glycol monomethyl ether, ethylene
glycol monoethyl ether, propylene glycol monomethyl ether,
tripropylene glycol monomethyl ether, ethylene glycol monobutyl
ether, diethylene glycol monomethyl ether, diethylene glycol
monoethyl ether, and any combination thereof, can be used.
These organic solvents can be used either singly or in admixture
according to need.
The novel laser ablation composition comprised of components VIII,
VIV or X when coated as a film on a substrate are either inherently
soluble in aqueous base developer prior to exposure to broadband
radiation or become soluble in unexposed area after a baking step
due to cleavage of acid labile protecting groups during a baking
step induced by acid originating from a thermal acid generator. In
either case, upon exposure to broadband radiation exposed areas of
the film become insoluble in aqueous base due to crosslinking.
Typical aqueous alkaline developers including hydroxides, for
example tetra (C.sub.1-C.sub.4 alkyl)ammonium hydroxide, choline
hydroxide, lithium hydroxide, sodium hydroxide, or potassium
hydroxide, carbonates, bicarbonates, amines and other basic
materials. In some cases and some applications solvent developers
well known in the industry may be used.
The currently disclosed novel laser ablation composition containing
VIII, VIV and X may further contain polymers useful for their
particular properties. For example, polymers with high acid values
can be added as additional polymer components to aid in the
development stage as well as the stripping stage, such as,
styrene-co-maleic anhydride-half ester, wherein the ester group may
impart certain properties to the composition.
The currently disclosed novel laser ablation composition containing
component X may also contain as additional components silicon-based
materials, capable of reacting with photo-generated free radicals
may also be used. These materials include, for example,
silsesquioxane full or partial cage materials, as well as ladder
materials, which can be included to impart improved toughness,
thermal stability and other desirable properties to the composition
and the final relief image. Acrylates, methacrylates, and vinyl
groups may be attached to the silicon material to impart
curability. An example is octa-acrylo-silsesquioxane type of
materials.
Another embodiment of the novel composition as previously described
is an embodiment where the wherein the conjugated aryl additive in
component b) has structure (I), and further where R.sub.2 and
R.sub.1 are independently chosen from hydrogen or an alkyl
group.
Another embodiment of the novel composition as previously described
is an embodiment where the where the conjugated aryl additive in
component b) has structure (II), and further where R.sub.3 is an
alkyl group and X is Cl.
Another embodiment of the novel composition as previously described
is an embodiment where the where the conjugated aryl additive in
component b) has structure (V), and where at least one R.sub.8 is
independently chosen from an alkoxy group, a hydroxyalkylene, or a
hydroxy group.
Another embodiment of the novel composition as previously described
is an embodiment where the where the conjugated aryl additive has
structure (VI), and where at least one R.sub.8 is independently
chosen from an alkoxy group, a hydroxyalkylene, or a hydroxy
group.
Another aspect of this novel composition is where the component a)
group is selected from (VIII), (VIV) or (X) and where further the
conjugated aryl additive in component a), the conjugated aryl
additive, is chosen from (I), (II).
Another aspect of this novel composition is where the component a)
group is selected from (VIII), (VIV) or (X) and where in the
component b), the conjugated aryl additive, is (I).
Another aspect of this novel composition is where the component a)
group is elected from (VIII), (VIV) or (X) and where further in the
component b), the conjugated aryl additive, is (II).
Another aspect of this novel composition is where component a)
group is selected from (VIII) and where the component b), the
conjugated aryl additive, is selected from (I) or (II).
Another aspect of this novel composition is where component a)
group is selected from (VIII) and where further the component b)
the conjugated aryl additive is (I).
Another aspect of this novel composition is where component a)
group is selected from (VIII) and where further in the component
b), the conjugated aryl additive, is (II).
Another aspect of this novel composition is where component a)
group is selected from (VIV), and where further in the component
b), the conjugated aryl additive, is (I) or (II).
Another aspect of this novel composition is where component a)
group is selected from (VIV), where further in the component b),
the conjugated aryl additive, is (I).
Another aspect of this novel composition is where component a)
group is selected from (VIV) where further in the component b), the
conjugated aryl additive, is (II).
Another aspect of this novel composition is where is where
component a) group is selected from (X), where further in the
component b), the conjugated aryl additive, is (I) or (II)
Another aspect of this novel composition is where component a)
group is selected from (X), where further in the component b), the
conjugated aryl additive, is (I).
Another aspect of this novel composition is where component a)
group is selected from (X), where further in the component b), the
conjugated aryl additive, is (II).
Another embodiment of the novel composition in any of the above
described embodiment is where the conjugated aryl additive absorbs
ultraviolet radiation strongly having a molar absorptivity between
about 220 nm and 310 nm of between about 10 and 1000 m.sup.2/mol.
In another embodiment of this aspect of the invention the molar
absorptivity is between 100 and 1000 m.sup.2/mol. In still another
embodiment it is between 200 and 1000 m.sup.2/mol.
Another embodiment of the novel composition in any of the above
described embodiment is where the conjugated aryl additive has a
molar absorptivity at 248 nm between 10 and 1000 m.sup.2/mol. In
another embodiment of this aspect of the invention the molar
absorptivity is between 100 and 1000 m.sup.2/mol. In still another
embodiment it is between 200 and 1000 m.sup.2/mol.
Another embodiment of the novel composition in any of the above
described embodiment is where the conjugated aryl additive has a
molar absorptivity at 308 nm between 10 and 1000 m.sup.2/mol. In
another embodiment of this aspect of the invention the molar
absorptivity is between 100 and 1000 m.sup.2/mol. In still another
embodiment it is between 200 and 1000 m.sup.2/mol.
Methods of Forming Images with Broadband Radiation
The current application further discloses methods of forming
negative relief images with all embodiments after exposure to
broadband radiation. The compositions of the current disclosure are
coated onto a chosen substrate and dried. The thus created film is
then imagewise exposed through a negative mask using broadband
radiation which output contains wavelengths between (350-450 nm)
suitable to generate free radicals. The patterns that are exposed
to the radiation cure or harden. Aqueous base developer is next
applied to the film, and the areas which were not exposed to
radiation are solubilized and removed from the substrate.
Coating can be accomplished by any of a number of coating methods,
such as, for example, spin coating, slot coating, dip coating,
curtain coating, roller coating, wire coating or other known
methods. The thus applied coatings are dried of their solvent, to
less than 5% solvent. Drying may be performed by hot plate heating,
convection, infrared or other known methods for removing solvent
from a coated film. In many thick film applications, imagewise
exposure energies of less than 1000 mW at wavelengths greater than
300 nm are needed, such as 365 nm, 405 nm, 436 nm and broadband for
instance between 350 and 450 nm. After exposure, an appropriate
developer is applied to the film, such as 0.25N tetrabutylammonium
hydroxide. The developer may be applied by spin coating, dipping,
spraying or soaking, and may be about room temperature or may be
heated depending on the solubility of the unexposed, as well as the
exposed, photoresist in the developer. Typical applications for
thick film photoresists require 3/1 aspect ratio, wherein the
photoresist at 30-60 microns thicknesses create holes and trenches
which are 15-70 microns wide.
Using either a coated film which has been blanket exposed with
broadband radiation and crosslinked, or a topographical negative
image created by exposure to broadband radiation through a mask
followed by aqueous base development the blanket exposed film or
remaining negative film in the negative image may be further
patterned by cold laser ablation employing an Excimer laser
emitting between 222 nm and 308 nm.
After removing the unexposed areas, patterns has been created in
the film with the surface of the substrate now capable of further
processing, such as, for example, electroplating metal into the
relief areas, creating metal lines, bumps, trenches and other
structures. The surface which has now been exposed may be subjected
to etching of materials on the substrate. After etching,
electroplating or other processing, the negative photoresist is
removed or stripped, expect in those cases where the negative
photoresist is designed to be a permanent material such as a
permanent dielectric. Both electroplating and etching processes are
well known in the art. Stripping solutions are generally strongly
alkaline solutions and are generally heated above 100.degree. F.
Often the photoresist is cured to well that the photoresist does
not dissolve on the stripping solution, but swells and is removed
as a gel.
One embodiment of this invention is a process comprising steps a),
b) and c) as follows: a) coating the composition of claim 1 on a
substrate; b) cross-linking the entire coating by irradiation with
broadband UV exposure; c) forming a pattern in the cross-linked
coating by cold laser ablating with a UV excimer laser emitting
between 222 nm and 308 nm.
In another embodiment of this inventive process the broadband UV
exposure is between 350 and 450 nm.
In another embodiment of this inventive process the broadband UV
exposure is between 350 and 450 nm the excimer laser emits at 248
nm.
In another embodiment of this inventive process the excimer laser
emits at 308 nm.
Another embodiment of this invention is a process comprising steps
a), b) c), and d) as follows: a) coating the composition of claim 1
on a substrate; b) cross-linking part of the coating by irradiation
with broadband UV exposure; c) developing the coating with aqueous
base removing the unexposed areas of the film, thereby forming a
first pattern; d) forming a second pattern in the first pattern by
laser cold laser ablating with a UV excimer laser emitting between
222 nm and 308 nm. In another embodiment of this process the
excimer laser emits at 248 nm. In a further embodiment of this
process the excimer laser emits at 308 nm.
EXAMPLES
The following specific examples will provide detailed illustrations
of the methods of producing and utilizing compositions of the
present invention. These examples are not intended, however, to
limit or restrict the scope of the invention in any way and should
not be construed as providing conditions, parameters or values
which must be utilized exclusively in order to practice the present
invention.
Unless otherwise indicated all chemical were obtained from Sigma
Aldrich (St. Louis, Mo.).
Polymer Synthesis Example 1
6.49 g of acrylic acid, 8.85 g of styrene, 21.62 g of hydroxypropyl
methacrylate, and 24.89 g of tert-butyl methacrylate were admixed
in 117.9 g of PGME solvent. The polymerization reaction proceeded
with stirring in the presence of 1.64 g of AIBN at 90.degree. C.,
under nitrogen for 18 hours. After cooling down to room temperature
the reaction mixture was precipitated in DI water. The white
polymer solid was washed and dried under vacuum at 50.degree. C.,
yielding 61.0 g (98% yield) with a weight average molecular weight
of 15496.
Formulation Example 1
35.34 g of the polymer prepared from Example 1, above, was admixed
with 21.66 g of propylene glycol monomethyl ether acetate, 14.14 g
of SR268 (from Sartomer Corp, Exton, Pa.), and 21.21 g of DHDMA
(from Sartomer Corp). After rolling overnight, 3.54 g of
Irgacure.RTM. 907 (2-Methyl-1((4-methylthio)phenyl)-2-morpholino
propan-1-one available from BASF) and 1.76 g of Irgacure.RTM. 819
(Bis(2,4,6-trimethylbenzoyl)-phenyl phosphineoxide available from
BASF) were admixed. 0.01 g of Megafac R08 (from Dinippon Ink and
Chemical Corp, Tokyo 103-8233, Japan), 2.00 g of
2-(4-methoxyphenyl)-4,6-bis(trichloromethyl)-1,3,5-triazine (MPTT)
and 0.25 g CGL 1198 inhibitor were admixed and the admix was rolled
for 2 days. The composition was filtered and spin coated on a
silicon wafer and dried on a hot plate for 5 min at 140.degree. C.
The dried coating was measured to be 50 microns thick. The resist
coating was exposed at 1200 mJ/cm.sup.2. The resulting film was
laser ablated (Table 1 and FIG. 1).
Formulation Example 2
35.34 g of the polymer prepared from Example 1, above, was admixed
with 21.66 g of propylene glycol monomethyl ether acetate, 14.14 g
of SR268 (from Sartomer Corp), and 21.21 g of DHDMA (from Sartomer
Corp). After rolling overnight, 3.54 g of Irgacure.RTM. 907
(2-Methyl-1((4-methylthio)phenyl)-2-morpholino propan-1-one
available from BASF, Ludwigshafen, Germany) and 1.76 g of
Irgacure.RTM. 819 (Bis(2,4,6-trimethylbenzoyl)-phenyl
phosphineoxide available from BASF) were admixed. 0.01 g of Megafac
R08 (from Dinippon Ink and Chemical Corp), 2.00 g of methoxy
naphthalene (MN) and 0.25 g CGL 1198 inhibitor were admixed and the
admix was rolled for 2 days. The composition was filtered and spin
coated on a silicon wafer and dried on a hot plate for 5 min at
140.degree. C. The dried coating was measured to be 50 microns
thick. The resist coating was exposed at 1200 mJ/cm.sup.2. The
resulting film was laser ablated (Table 1).
Formulation Example 3
35.34 g of the polymer prepared from Example 1, above, was admixed
with 21.66 g of propylene glycol monomethyl ether acetate, 14.14 g
of SR268 (from Sartomer Corp), and 21.21 g of DHDMA (from Sartomer
Corp). After rolling overnight, 3.54 g of Irgacure.RTM. 907
(2-Methyl-1((4-methylthio)phenyl)-2-morpholino propan-1-one
available from BASF) and 1.76 g of Irgacure.RTM. 819
(Bis(2,4,6-trimethylbenzoyl)-phenyl phosphineoxide available from
BASF) were admixed. 0.01 g of Megafac R08 (from Dinippon Ink and
Chemical Corp), 2.00 g of 1,5-dihydroxynaphthalene (DHN) and 0.25 g
CGL 1198 inhibitor were admixed and the admix was rolled for 2
days. The composition was filtered and spin coated on a silicon
wafer and dried on a hot plate for 5 min at 140.degree. C. The
dried coating was measured to be 50 microns thick. The resist
coating was exposed at 1200 mJ/cm.sup.2. The resulting film was
laser ablated (Table 1).
Formulation Example 4
35.34 g of the polymer prepared from Example 1, above, was admixed
with 21.66 g of propylene glycol monomethyl ether acetate, 14.14 g
of SR268 (from Sartomer Corp), and 21.21 g of DHDMA (from Sartomer
Corp). After rolling overnight, 3.54 g of Irgacure.RTM. 907
(2-Methyl-1((4-methylthio)phenyl)-2-morpholino propan-1-one
available from BASF) and 1.76 g of Irgacure.RTM. 819
(Bis(2,4,6-trimethylbenzoyl)-phenyl phosphineoxide available from
BASF) were admixed. 0.01 g of Megafac R08 (from Dinippon Ink and
Chemical Corp), 2.00 g of 9-fluorenone (9-FN) and 0.25 g CGL 1198
inhibitor were admixed and the admix was rolled for 2 days. The
composition was filtered and spin coated on a silicon wafer and
dried on a hot plate for 5 min at 140.degree. C. The dried coating
was measured to be 50 microns thick. The resist coating was exposed
at 1200 mJ/cm.sup.2. The resulting film was laser ablated (Table
1).
Formulation Example 5
35.34 g of the polymer prepared from Example 1, above, was admixed
with 21.66 g of propylene glycol monomethyl ether acetate, 14.14 g
of SR268 (from Sartomer Corp), and 21.21 g of DHDMA (from Sartomer
Corp). After rolling overnight, 3.54 g of Irgacure.RTM. 907
(2-Methyl-1((4-methylthio)phenyl)-2-morpholino propan-1-one
available from BASF) and 1.76 g of Irgacure.RTM. 819
(Bis(2,4,6-trimethylbenzoyl)-phenyl phosphineoxide available from
BASF) were admixed. 0.01 g of Megafac R08 (from Dinippon Ink and
Chemical Corp), 2.00 g of 9-anthracene methanol (9-AM) and 0.25 g
CGL 1198 inhibitor were admixed and the admix was rolled for 2
days. The composition was filtered and spin coated on a silicon
wafer and dried on a hot plate for 5 min at 140.degree. C. The
dried coating was measured to be 50 microns thick. The resist
coating was exposed at 1200 mJ/cm.sup.2. The resulting film was
laser ablated (Table 1).
Formulation Example 6
35.34 g of the polymer prepared from Example 1, above, was admixed
with 21.66 g of propylene glycol monomethyl ether acetate, 14.14 g
of SR268 (from Sartomer Corp, Exton, Pa.), and 21.21 g of DHDMA
(from Sartomer Corp). After rolling overnight, 3.54 g of
Irgacure.RTM. 907 (2-Methyl-1((4-methylthio)phenyl)-2-morpholino
propan-1-one available from BASF) and 1.76 g of Irgacure.RTM. 819
(Bis(2,4,6-trimethylbenzoyl)-phenyl phosphineoxide available from
BASF) were admixed. 0.01 g of Megafac R08 (from Dinippon Ink and
Chemical Corp, Tokyo 103-8233, Japan), 2.00 g of 9-Phenanthrol
(9-Ph), and 0.25 g CGL 1198 inhibitor were admixed and the admix
was rolled for 2 days. The composition was filtered and spin coated
on a silicon wafer and dried on a hot plate for 5 min at
140.degree. C. The dried coating was measured to be 50 microns
thick. The resist coating was exposed at 1200 mJ/cm.sup.2. The
resulting film was laser ablated (Table 1).
Formulation Example 7
35.34 g of the polymer prepared from Example 1, above, was admixed
with 21.66 g of propylene glycol monomethyl ether acetate, 14.14 g
of SR268 (from Sartomer Corp, Exton, Pa.), and 21.21 g of DHDMA
(from Sartomer Corp). After rolling overnight, 3.54 g of
Irgacure.RTM. 907 (2-Methyl-1((4-methylthio)phenyl)-2-morpholino
propan-1-one available from BASF) and 1.76 g of Irgacure.RTM. 819
(Bis(2,4,6-trimethylbenzoyl)-phenyl phosphineoxide available from
BASF) were admixed. 0.01 g of Megafac R08 (from Dinippon Ink and
Chemical Corp, Tokyo 103-8233, Japan), 2.00 g of Pyrene, and 0.25 g
CGL 1198 inhibitor were admixed and the admix was rolled for 2
days. The composition was filtered and spin coated on a silicon
wafer and dried on a hot plate for 5 min at 140.degree. C. The
dried coating was measured to be 50 microns thick. The resist
coating was exposed at 1200 mJ/cm.sup.2. The resulting film was
laser ablated (Table 1).
Formulation Example 8
36.06 g of the polyGK65 (from Dupont) was admixed with 21.66 g of
propylene glycol monomethyl ether acetate, 14.14 g of SR268 (from
Sartomer Corp), and 21.21 g of 2,5-dimethyl-2,5-hexanediol
dimethacrylate (DMHMA) (from ENF). After rolling overnight, 3.54 g
of Irgacure.RTM. 907 (2-Methyl-1((4-methylthio)phenyl)-2-morpholino
propan-1-one available from BASF) and 1.76 g of Irgacure.RTM. 819
(Bis(2,4,6-trimethylbenzoyl)-phenyl phosphineoxide available from
BASF) were admixed. 0.01 g of Megafac R08 (from Dinippon Ink and
Chemical Corp), 2.00 g of
2-(4-methoxyphenyl)-4,6-bis(trichloromethyl)-1,3,5-triazine (MPTT)
and 0.25 g CGL 1198 inhibitor were admixed and the admix was rolled
for 2 days. The composition was filtered and spin coated on a
silicon wafer and dried on a hot plate for 5 min at 140.degree. C.
The dried coating was measured to be 50 microns thick. The resist
coating was exposed at 2000 mJ/cm.sup.2. The resulting film was
laser ablated (Table 1).
Formulation Example 9
36.1 g of Cresol novolak resin (from AZ Electronic Materials) and
5.3 g Cymel 301 as crosslinker (from AZ Electronic Materials) were
admixed with 56.3 g of propylene glycol monomethyl ether acetate.
After rolling overnight, 1.1 g of NIT PAG (available from
Heraeus-Daychem) and 0.02 g of APS437 (available from available
from D.H. Litter Co) and 2.00 g of
2-(4-methoxyphenyl)-4,6-bis(trichloromethyl)-1,3,5-triazine (MPTT)
were admixed and the admix was rolled for 2 days. The composition
was filtered and spin coated on a silicon wafer and dried on a hot
plate for 3 min at 140.degree. C. The dried coating was measured to
be 50 microns thick. The resist coating was exposed at 1200
mJ/cm.sup.2. The resulting film was performed laser ablation.
Comparative Formulation Example 1
35.34 g of the polymer prepared from Example 1, above, was admixed
with 21.66 g of propylene glycol monomethyl ether acetate, 14.14 g
of SR268 (from Sartomer Corp, Exton, Pa.), and 21.21 g of DHDMA
(from Sartomer Corp). After rolling overnight, 3.54 g of
Irgacure.RTM. 907 (2-Methyl-1((4-methylthio)phenyl)-2-morpholino
propan-1-one available from BASF) and 1.76 g of Irgacure.RTM. 819
(Bis(2,4,6-trimethylbenzoyl)-phenyl phosphineoxide available from
BASF) were admixed. 0.01 g of Megafac R08 (from Dinippon Ink and
Chemical Corp, Tokyo 103-8233, Japan), and 0.25 g CGL 1198
inhibitor were admixed and the admix was rolled for 2 days. The
composition was filtered and spin coated on a silicon wafer and
dried on a hot plate for 5 min at 140.degree. C. The dried coating
was measured to be 50 microns thick. Different resist coatings was
exposed at 300 mJ/cm.sup.2 (25% cure) or 1200 mJ/cm.sup.2 (100%
cure). The resulting film was laser ablated but all coatings had no
effective capacity to undergo laser ablation to form contact holes
(FIG. 1).
Broadband and Laser Ablation (with 308 nm) Processing Results:
Laser Ablation Comparisons.
The laser ablations results are summarized in Table 1. These
results were obtained from coatings on silicon wafers using
Formulation Examples 1-9 and Comparative Example 1. These coatings
were obtained by spin coating the formulation unto the wafers at a
spin speed of 1000 rpm to 2400 rpm then baking the coating at a
temperature of 140.degree. C. for 5 min using a Suss ACS300 plus
track giving coating having a thickness of 50 microns. The coated
wafer were then "cured" with a Broadband radiation exposure
(350-450 nm) using a Suss MA-200 Mask Aligner. The cured coatings
prepared with Formulations Examples 1-7 and 9 were exposed to 1200
mJ/cm.sup.2 (100% cure) and Formulation Example 8 to 2000
mJ/cm.sup.2 (100% cure), while the coatings prepared from the
Comparative Example 1 where either exposed to 1200 mJ/cm.sup.2
(100% cure) or 300 mJ/cm.sup.2 (25% cure). The cured wafers were
ablated using a Suss Excimer Laser Stepper: model M410. Excimer
lasers (XeCl, 308 nm and KrF, 248 nm). These Laser ablation tools
are routinely used in various microfabrication, micromachining, and
surface modification applications. The excimer laser is very
effective in polymer ablation due to the short pulse duration and
high peak power. The fluence was in the range of 200-1000
mJ/cm.sup.2 and frequency was 100 Hz. The ablated vias were
characterized by top down scanning electron microscopy (SEM). As
summarized in Table 1 all coating prepared form formulations
Example 1-9 gave good laser ablation which was used to produce via
contact holes ranging in size from 40 to 200 microns having good
wall angles of at least 78.degree..
TABLE-US-00001 TABLE 1 Summary of the Formulation Examples and
Conparative example Formulation Ablation results Example #
Composition Types Addtives with 365 nm Laser 1 X MPTT Ablated 2 X
MN Ablated 3 X DHN Ablated 4 X 9-FN Ablated 5 X 9-AM Ablated 6 X
9-Ph Ablated 7 X Pyrene Ablated 8 VIV MPTT Ablated 9 VIII MPTT
Ablated Comparative #1 X N/A No ablation
FIG. 1 shows a comparison of top down SEM pictures which
illustration the attempted formation of via holes with laser
ablation using a 308 nm laser in coatings prepared from
formulations which either do contain, or do not contain a laser
ablation additive MPTT.
Specifically, coatings prepared with "Comparative Formulation
Example 1" which does not contain the laser ablation additive MPTT
give no effective ablation to form a contact hole. This is true
with either a film which is UV cured at 25% or 100% prior to laser
ablation with the 308 nm laser. In contrast Example 1 with 2 wt %
of MPTT shows an ablation rate of 1.49 .mu.m/pulse and gives via
hole with a 78.1.degree. sidewall angle was achieved.
* * * * *
References